i agree with MM1873 if your problem is muscular, physical therapy will help. if not, you may need surgery. i would see a specialist who can get an MRI to determine the cause of your problems.
as for dental appts, a good dentist and hygienist will be able to clean your teeth with the limited opening. just let them know that you have TMJ issues so they will not make you hold your mouth open for long periods of time.
as for surgery, they will put the tube down your nose instead of your throat when you have TMJ surgeries.
and eating, you just get used to eating soft foods and not chewing. you get really good at blending things!
my advice is to get to a specialist who can figure out the underline cause of your problems