What Causes Gradual Decrease In Weight After A Bypass Surgery?

i have lost 20 pds in two months i had bypass in 2005 and kept a healthy weight of low 180 he stressed not i dont what kind of dr to see the dr that did the surgery is nowhere to be found im depressed on wellbutrin klonipin and i look awful dropped 2 sixes and feel unhealthy all im really scared i live in nj area south amboy of course all my skin is sagging my family things im deterating i knew someone would ask for money im onSS and have no extra money what dr should i see