I am sorry but I have to speak up here. I have SEVERE anxiety and it sounds like you have a pretty hefty case of anxiety on your hands as well. Not so sure if it's from the methadone or if you had it prior to the drug use and just didn't realize it because it was masking the anxiety. Anyway, please do not freak out about Klonopin. This is the deal and as I said before - it can be addicting. When you were on methadone, how frequently did your doctor give you your script? Was it weekly, twice a month, every day or what? I'm just wondering how you were able to control your methadone use.
Let me give you a real life situation. I was on KLONOPIN for about two years and I was taking them everyday. Normally, about .5 - 1 mg per day, every day for two years. I got pregnant and went to my OBGYN and of course, told him my concern. He told me to take .5 every other day for two weeks and then stop. Well, I did and had no withdrawal symptoms whatsoever. Now, I was preg and in the early stages so I was tired and stuff but it was just like all of my other pregnancies (well, I was sicker but the entire pregnancy, not just when I got off of those pills... I think it was because I had a girl and I've heard you get sicker w/girls). Anyway, bottom line is I didn't really have withdrawals and I only weaned for two weeks. I'm sure this is pretty unusual but if you are on it and when you decide to get off you taper appropriately, I just don't think it's going to be a nightmare for you. If you truly need a benzo for anxiety, then take it AS NEEDED. Try to skip nights and just try to not get as dependant on it. However, if you find you need it EVERY day, then take it every day but no more than what is prescribed - EVER. And then if/when you want to get off, then you can taper VERY slowly (I would NOT recommend tapering in two weeks--- it was stupid for my doc to do that as I could have had a seizure) but it did work for me but I do think I'm unusual.
Bottom line, if you need it - then quit worrying about it (only make you need it more) and take it as prescribed. It's for anxiety and obviously, you have it. Just quit worrying about it. Think of it this way - I am on Suboxone because I cannot stop abusing pain meds without it. If I get off of it, I'm very afraid I will not be able to control my cravings so I stay on it knowing there will be withdrawals when I stop. However, I do what I have to do to be sane TODAY! That's all.