The issues are so longstanding and so many that I have no advice on how to fix it. What I would advise is for you to see if you can have a consultation with a divorce attorney to see where would would stand financially if you left.

Also, you should probably consider updating or gaining skills to take into the job market, because whatever support you are legally entitled to will not cover all your expenses, especially since your husband is disabled and probably not making what he once made.

Have you considered taking a full-time job (since your youngest is a teen)? Perhaps being out of the house will keep you from getting overly involved in what's going on with him or what his family is doing or not doing.