You're having physical problems because you're slowly killing your body. I'm sure someone has said it on here before but the definition of insanity is doing the same thing over and over again expecting different results. That's what you are doing. Yes, therapy is uncomfortable, but yes it does help and no I don't know exactly why. Like you said there is nothing you can do to keep your mom out of your life so you might as well figure out what your problems are with her and make the best of them.