Weight, disabilities, & 1st trimester blues

I am completely freaking over my weight this pregnancy!! I gained a lot with my first (55lbs?) because my midwife and husband were always in me about eating enough in the begining then all the sudden I blew up :-( I couldn't work out because my hips kept dislocating and I had a lot of pain issues. We didn't know then I suffer from a genetic condition at that time that would later explain all my mysterious and invisible ailments. Nobody believed me and it was hard. Now I'm paranoid about how I will hold up several years later for a pregnancy that is drowning me in depression and fear while I'm constantly starving!! I am carful to not eat a lot, but then I'm afraid I'm not eating enough and spiral on down from there.... Help! Anyone else struggling with something similar?