I can identify with this, and around the end of last semester I ended up asking these awesome people the same question.
This semester, I was able to tackle it a little better - so I am going to tell you what I did.
You have to realize your boundaries. Projects are awesome, and especially when you're extremely good at them - it can be super tempting to say yes or initiate a dozen projects at once. Tone it back, but also don't take on to few. It's good to be a generalist, but you have to maintain balance.
You have to break down your priorities and projects. Don't think of projects as a whole, break them down into sub-priorities I guess. Section off a portion of a project, and say "today I'm going to do this". One of the best pieces of advice I ever got from someone on here is that you can think of things in terms of investments.
I don't know what you tell you about work - If you don't care about what you're doing, you don't care about what you're doing. Do you like your job? Should you look for something different?
Worrying that these issues are going to affect your classes is a good thing. You've already done what most people either cannot do or they are unwilling to you - You've admitted you're the problem, and you're looking for a solution. The fact that you've identified that something about you needs to change is huge. Good job.
Lastly - When you start classes this fall - Commit to doing an hour of day of schoolwork. That's it - just one hour. Most likely, once you get working - the ball will just start rolling. Set aside that hour. Put it in your phone.
If you think there's even a tiny possibility that this is depression - Talk to someone. Your school should have counselors available to you, as the VA is sometimes not very reliable or willing to work around time sensitive issues. Take advantage of that resource. The more you are willing to be open about this, the more likely you are to find motivation.
It's hard, but it's not impossible. Do things in tiny increments, break down your priorities into smaller priorities, and continue to be honest with yourself.