Aindrea, please please please go to the Dr. There is no need to put yourself through the stress of not knowing!
Personally I think if your discharge smells offensive then you need to get it checked out. It's not normal for your discharge to smell horrible. You also say that this has been going on for 2 years??? Aindrea I don't want to scare you but by not going to the Dr for a checkup you could be doing damage to your reproductive system. I'm not saying that your discharge is an indication of a serious problem, but if it is and you leave it for another 2 years before getting looked at it, you could make yourself really sick.
On the other hand it's probably something minor that your Dr can give you something to clear it up and you'll be as good as gold!
Deep breath....make an appointment sweetie.