Any Advice Can Help

I am 18 years old and when i was younger(about 4 years ago)i was bulimic. I was bulimic for about 2 years because i over heard a friend talking about it, but after a while i realized the harsh side effects(head aches,fatigue) & i stopped making myself vomit after every meal. i still over eat often, but my MAIN problem is that now i cannot go to the bathroom on my own..ever. My guess is that since i was vomiting, the food never reached alot of important organs and maybe those organs have stopped working. I wont have a bowl movement for days-to-weeks unless i use some kind of laxative. i recently started seeing a therapist for Colon Hydro Therapy. They said that once my colon was entirely cleaned out i would be able to have a bowel movement once a day. I feel like i became dependent on Colon Hydro Therapy because now the only time i EVER have to use the restroom is during my session (which is exactly what a session is supposed to make you do, use the restroom..) My therapist said its impossible to become dependent, but unless i use a laxative, or colon hydro therapy, i will go WEEKS without having a bowel movement. my appetite stays the same so i OFTEN appear pregnant because i continue to eat normally but i never have a bowel movement so my stomach continues to grow and grow. its horrible and embarrassing. i turn into a grumpy person when i cant go because of all the toxins that build up inside me. Not being able to go to the restroom on your own, in addition to only having to use the restroom once every 2 weeks or so, is NOT normal. i need help please, anything will help and im open to all ideas.