Stop taking METHADONE cold turkey?

Hi, Heres my question. I had a problem taking oxycontin after a lung surgery I got hooked on them. I was sent to a methadone clinic and thought I would be there 6 months top. Well two years later, 40 pounds heavier I am still here taking 90 mgs a day. I am so tired of going there and want it over so that I can be me again, the normal me that is. I need to hear from people who quit cold turkey, what to expect and helpful ideas on what to do to get through it. How long will it take to get better, etc...