It might be easier for someone to offer suggestions if you tell us the general area you live in.
I don't know if any pediatric dentists would take you, but why don't you call some and ask the receptionist? Tell them your situation. If they can't take older patients, they may offer suggestions for you.
Editing to add: Another place you can start is by asking your primary care doctor for suggestions (if you have one). Or, if you have a therapist or social worker, you can ask them too.