I see in another post that you're only 26, pretty young to feel like you do. When you talk with your doctor (you mentioned in the other post that you're seeing your neuro, soon) talk with him about the possibility that you might also be suffering from depression. Depression can happen with MS -- a chemical imbalance in the brain, caused by a lesions in the wrong place. Lots of folks take antidepressants, which also can sometimes help with fatigue, and even pain, so it's worth asking about it.
You should also ask about going to see a physical therapist. If your walking is a problem, and that is why you're staying inside, you might need to learn how to use a cane, which can help with stability and get you moving more. I use a wheelchair full time, but still get out and about, doing things, particularly when my husband is around to help. I thought you were all alone, but you said you have a fiance; I'm sure he'd be glad to help you with canes or forearm crutches, if it meant you'd go out and do things. Even an afternoon shopping, or hanging out at the mall, or going out for dinner, will help your overall attitude.
YOu say your fiance is trying to "deal with" you. Exactly what is it that you're asking of him? What are you not able to do by yourself, that you need help with? Talk about that here, and maybe we can offer some ideas about how to increase your independence, and build up your confidence about getting out and about in the world.
...I am not a doctor, nor health professional, and don't pretend to be one, here.....