You have a lot of issues that you have mentioned - all stemming from this. Get a local attorney for a consult. Sit down with him and explain. Then chart a course and stick to it. Good luck.
Every case is fact sensitive. Without knowing all the facts, no attorney can give you specific advice that you can totally rely on. ANY answer here is just trying to help lead you in the right direction. That direction is to sit down with a local attorney and give them ALL the facts in your case, so that you can get good legal advice. Certainly any response that I give should not be considered legal advice or counsel that can be depended upon.
This is a really difficult situation. Unfortunately, as long as this matter is showing on a background check, even though it is a deferred adjudication, you will struggle to find work. You need to make sure you contact with your probation officer and that he or she is familiar with the struggles that you are having. I would suggest that you ask your probation officer if he or she has job resources that you can access - sometimes the probation officers can be helpful in this regard. You may want to consult with an attorney to determine if there are any conditions of your probation that can be waived (fees, classes, etc). Good luck to you.