Self Doubt

I just read a book about homeschooling during the first year, so I know that self-doubt is completely normal, and to be expected. But I still don't like it.
I found out that Brigham would have been in the same class as his friend Adam (whom he rode to and from school with most of last year), and Joseph would have been in the same class as his best friend Kenny.
Things have been going great with Brigham, but he would do just fine anywhere, even stranded on the North Pole (as long as he had some paper and a sharpened pencil).
I'm struggling with Joseph. He is still doing the same thing where at some random point in our lessons, he just decides he's done and will no longer cooperate. On Thursday we got ALMOST through all our lessons (I was congratulating myself), all the way to the very last line of his science lab report, and he decided he was done. He wasn't going to do it. Friday it was during our 2nd lesson, handwriting, that he decided he would not cooperate. He was doing his "P's" wrong, and I was trying to show him the correct way, and he got angry and refused to listen to me or watch what I was doing. I was just tired and worn out from dealing with him so I told him if he didn't want to do handwriting, then to just go outside and play. Which he did for the rest of the morning. Maybe what he really needs is some decompression time from everything that has happened this summer. Or maybe he's just being difficult because I'm letting him be.
I have no leverage over him because I can't back anything up. I can't say he has to go to his room if he's going to misbehave, because I can't make him go to his room. I can't say he won't be able to go to the park or whatever outing if he doesn't behave, because I can't leave him home alone, and it's not fair to deny Brigham and Moses. He is so strong-willed, that when he is in the moment during one of these episodes, there is literally nothing that will motivate him to just stop it. I know I was like this to a large degree when I was a kid, and I don't know what would have worked with me either!
I'm also so disappointed in soccer. I signed up the boys for soccer in our community's sports league. It is the only youth soccer organization in North/Northwest Austin. I really wanted just a simple, low-key soccer team with one practice a week, and one fun game on the weekends. Instead we get placed on a team that practices on Sundays and Wednesdays (so we already can only go to one practice), and "plays up" (not sure if that is the right term) against older, bigger teams. And everyone on the team except my boys have played soccer for the past two years. I was told it's ok to only go to one practice a week if we also go to the "drills practice" after Wednesday's practices, and attended a "Development Training" class on Monday nights. Way, way more of a time commitment than I anticipated.
We had our first practice on Wednesday. The boys did ok for the first 45 minutes (just team practice), although I could see Joseph getting frustrated and I could tell both of them really didn't know what was going on. Then there was "drills practice," which apparently goes on for TWO HOURS!!! It was SO hot outside, and Brigham forgot his water bottle, so the one they were sharing quickly ran out. Both boys participated for a while, then I could see Joseph at the far side of the field just standing there, his head sort of down and to the side, like he does when he disengages. I saw the coach go over and talk to him, but he wouldn't respond. Finally he takes his ball and runs off the field and sits under some bushes and won't move. Rachel went over to try and talk to him, but he wouldn't respond at all. Brigham practiced for a little more, but when the kids all started running laps (after an hour and a half of practice in 95 degree weather), he was just pooped! He came over to me, all red-faced and sweating and said he wanted to go home.
So we got his stuff and started back to the van. I can BARELY walk at this point because of the heat, and Rachel had to practically carry me across the grass, up the gravel path, across the bridge, and to the van. I'm about in tears because this is NOT what I wanted, and Joseph refuses to come to the car. We have to back out and just about drive out of the parking lot before Joseph comes running back to the van.
And boy, is he in a MOOD! He starts hitting Brigham, kicking the back of my seat, and finally Rachel pulls over into a parking lot to try to get control over the situation. She takes him out of the car, and he's totally out of control, hitting and kicking, and just completely out of it. Finally she wrestles him back into the car and I sit on the middle seat and hold him to prevent him from kicking and hitting Brigham (poor boy, he's sitting there crying, not knowing WHAT he's done to his brother to deserve all this).
When we got home I stayed in the van with Joseph to try to calm him down and figure out what was going on. He finally calmed down, but couldn't really tell me what was wrong apart from the fact that his coaches kept mixing up him and Brigham, or when they got it right, called Joseph "Joe," and he said that the drills were "just like P.E. and Tae Kwon Do," whatever that means.
I know it just wasn't what he was expecting. Frankly, it wasn't what I was expecting. I was SO sad, because earlier that day we had gone to Academy and bought the boys soccer cleats, soccer shorts, and size 3 soccer balls. Joseph was just so excited, he immediately changed into his soccer gear and wore it for the rest of the day until we left for practice. I so wanted something that he will really like and feel like he is good at. And now he's on a team that has played for 3 years, so he feels completely incompetent and over his head. I think Joseph could really enjoy soccer, if it had been less intense than it was. It was just really overwhelming for their first day.
I hope it gets better. We'll stick it out for a few weeks. Their first game would have been today, but the games all got cancelled because of Ike (although we haven't gotten more than a few sprinkles and some breeziness). Then his coach called and said there would be a friendly scrimmage against one of the other under-8 teams, which would have been perfect because it would have been less pressure and less competition, and would have been a good first game experience for the boys. But they had been invited to a friends' house (Kenny), and I just couldn't cancel that.
So now I'm feeling pretty low. I don't know how to help Joseph. I'm wondering if homeschooling is making him worse. I'm feeling bad that the boys aren't getting to go to class with their buddies. I'm so disappointed and worried about soccer. I'm continually frustrated by my physical limitations. I feel horrible that I can't even go to my kids' soccer practices (no way can I do it without someone to help me get down and back from the field, and drive us home afterward). I can't take them on cool field trips or hikes in the woods. It all just stinks!!
I'm praying so hard every day to know what to do-- how to conduct lessons, how to handle Joseph, how to give attention to Moses and Brigham, how to be able to run my life again! But right now it all sure seems so cloudy.