Hi lostnlonelydee,
I'm sorry you are struggling with your feelings today. I know how hard it is when they wash over you, after having felt better for awhile. It is a normal part of grieving; sometimes it feels like we have slid back to square one, but we really haven't. We're just processing another piece of the grief.
If you can, ride the wave of sensations in your body. Let yourself cry when you feel safe to do so. Try not to let your mind make the sensations mean anything about your future. It's possible to feel what is coming up (in the body) without running a terrible story with it.
During my relationship and after the breakup, I experienced skin problems, weight loss, sleep disturbances, and back pain... .I'm sure there is more, but that's what I remember at the moment. I would not be surprised if your hair loss is connected to stress, as

Larmoyant pointed out. I think getting it checked is a good idea, regardless.
Hang in there, lost. Things really do get better. Unfortunately the only way out is through. We're here for you.
heartandwhole