Advice on gaining weight?

okay, so long story short I had an emergency c-section about 8 months ago & was prescribed narcos to help with the pain but they also suppressed my appetite bad. For the month & a half I was taking them I couldn't eat more then half a meal a day to every other day. Since getting off them the habit has stayed. I just can't physically eat 3 meals a day. I'm up to about a meal & a half a day & even that makes my stomach hurt but at the same time I can still feel hunger pains. At this point I'm 5'7" & 103 lbs & was wondering if any of you have any advice? I'm gonna hopefully go to my pcp to talk about it soon. Just wondering if any of you have gone through anything similar & what ya did about it? ty!