I am so sorry you are being treated this way. My husband and I have an adopted child that is handicapped. We have been through some of the situations you mentioned.
I can't help with all the problems but I have an idea for the mail being stolen. You can ask that the mail carrier deliver directly to the house. We have disabled renter's that have done this. When you purchase the box, get the kind that hooks directly onto the house and has a lock.
Remember HOA President's are elected.
Metropolitan Fair Housing Council, 1500 Northeast 4th St., Ste. 204, OKC, OK 73117 Phone: 405-232-3247
Legal Aid of OKlahoma- Phone: 405-521-1302 or 1-800-421-1641
Oklahoma Human Rights Commission, 2101 N. Lincoln Blvd., Room 480, OKC, OK 73105 Phone: 405-521-3441 or 1-888-456-2558