Oh Nightshift, I'm sorry you have to go through this.
Chances are your brain has turned to poop is because of this big news you have been hit with. It's a lot to process! You're preoccupied with all going on in your life-- particularly this new dx. Of course you're going to forget your partial! Gosh, who wouldn't! The cruddy thing about MS is that like you said---- you don't know what road you will end up traveling. But I worked neurology right out of LPN school, and we saw a lot of MS patients--- most having the relapsing-remitting type. After the initial jolt of the dx had worn off, these people managed their illnesses very well. Most took very good care of themselves, trying to get enough sleep and to keep their stress levels as low as they could. Their exacerbations were usually pretty infrequent.
You need to do what ever you need to do to learn about this change in your life, and make changes in your life to adapt to it. The changes will probably be pretty minimal, and actually they'll be pretty helpful to you in other ways. Good quality sleep is good.... less emotional and physical stress is good. Just take everything one step at a time, and life will be good. You'll finish up this school thing at your own pace, as everyone should.
You're gonna be ok. No-- better than that, you're gonna be great.