Severe nosebleed was given what i can only guess was a clotting medicine at the doctor this morning. but now i'm feeling achy and very weak?

Nosebleed: I doubt the two have much to do with one another. It is possible that you had a viral infection which is causing the achy and weak sensation, bu this typically would not give you a nosebleed. Feel better.

May have bleed: Significantly . Acute blood loss can lead you to have low blood pressure and increased heart rate . If condition is not corrected , it may lead to a serious condition called shock. I do not believe you are going through this but it is something to think about . Take more fluid , if symptoms persists , see your doc of go to ed.