First let me say thanks for your service.

Second, Algebra is doable. It doesn't seem so right now, but it is. The thing is to learn the steps in the appropriate order.

With your TBI that may be difficult. But don't give up hope yet.

I had difficulty learning math because I had so much anxiety over it. That affected my learning the steps and recalling them.

Please talk to the instructor. Tell him you do care but that you are finding it difficult. If he is any good as an instructor he will want you to succeed.

Not all math instructors are any good. Just because someone can do math doesn't mean they can teach it.

This person may not be good for you. So you will need to find someone to tutor you. In the meantime you can do math problems just below where you are having trouble and build your skills that way. There are many math books out there to teach yourself.

Good luck, keep trying. It's worth it.