Tapering zoloft has drastically affected my behavior. example: i've quitted the things i used to do like clubs, hobbies, college..etc. is this normal?

No, it's not normal: It sounds like since you were doing these things before - clubs, hobbies etc-when you were on the Zoloft, that the medication had positively affected your depression and you were improved, and now that it is being tapered you are again showing signs/symptoms of depression. Talk to the prescriber - it sounds like you need to be back on it or another medication if the Zoloft was causing side effects