Hi guys. I'm a 19 year old guy, around 5'8", and I used to weigh around 120-125 lbs. Over the last month or two i've dropped to 113! That is very low for my size, and on top of that, I'm having some other issues. Sometimes I feel tired or weak, and I notice that sometimes when I move my limbs, they feel almost like when you fall asleep with an elevated arm. The tips of my pinkies still have feeling, but they feel very slightly less sensitive than normal. My posture has been pretty bad over the last little while, I probably haven't been eating as regularly and as properly as I should (lots of sandwiches and cereal), and I'm doing a LOT of walking. I'm a bit worried though, can anyone help me? And I'm wondering if maybe my blood pressure dropped?

I'm going to the doctor on Tuesday, but I'm a bit worried and would like some input. Thanks!