I recently went through something pretty traumatic where I was brainwashed by my former room mates. Now that i finally left I still fear they will find me and turn everyone against me. Do I need to see a therapist?

If you really believe you were brainwashed ... You DEFINITELY need to see a therapist. 

People who are actually brainwashed can't "deprogram" themselves.

I think your use of brain wash may be somewhat extreme. At your age it is quite normal to feel that in some situations you just don't fit it in. For many teens their is a craving to be accepted that will cause them to do things that they don't want just to get acceptance. Here is a link to give you some food for thought.

www.jw.org/en/bible-teachings/family/teenagers/ask/dont-have