Has Bulimia and Ephedrine ruined my metabolism forever?

I suffer from Bulimia, Binge ED, with frequent episodes of restricting. I have been abusing ephedrine and caffeine on and off for 3 years now. I go through differenct cycles of either binging/binging and purging/starvation/restriction that last anywhere from a few days to a few months. I don't want to be this way, but there I have no insurance and the free programs have no openings, so there's no need to try to knock some sense into me...I wish I could go back in time and do things differently. In an effort to cut some of my bad habits, I tried giving up ephedrine...Thats when I noticed that I seem to have an extremely slow metabolism if Im not on it. On days that I eat anything small amounts of food without purging, I gain weight. It's not like I've been purging every single thing I ate for the past 3 years, so my body isn't in starvation mode. I'm not underweight either. I think it has to do with the ephedrine. Any experts on the topic that can give me some background and maybe some advice on how to fix myself? I'd really appreciate it. Everything I read online seems to be an ad trying to sell something, so I really dont know what I can trust :/