Seek help now. I went to group OCD therapy and what i got from it is you have to keep trying to poop no matter what. just sit on the toilet even if nothing happens. and i think talking to a pyschotherapist can help in order to vent and release some of the stress.
I've often been where you are (just last night, i broke down in tears because my parents are coming back from vacation and i recently moved back in with them after graduating university and living on my own)but you have to stay strong and try and find new ways to poop. creating new routines and trying to go every opportunity you have. two weeks without going to the bathroom is torturous.
I would also advise to tell someone you are close with. a huge fear of mine, when it comes to telling someone about this problem, is that they will not get the scope of it or how much it affects my life. it is a very quiet issue that hurts so much more than anyone can realize, however i urge you to not think about this and tell someone you are close with. if your family knew about this problem, maybe they can create routines to help you out.
sorry for blabbing on and on. i just hope you are alright. deal with this while you are young, because it doesn't get better on its own.