Feeling sad

Im am feeling so hopeless. I am 52,unemployed.and underweight. Over the summer I spranged my foot and needed to hold on to the shower rod to step in and out of the shower. When I was getting out of the scale I saw myself in the mirror . I was a skeleton. I borrowed a scale and was horrified to realize my weight was 120 lbs(I'm 6 foot) since than I haven't been the same person. I don't know what my weight was before and I don't know how I let this happen. I have put on 12 pounds since but anxiety and worry is killing me. I feel like a pathetic old fool who is useless. I have never felt more hopeless..