Weight loss while breastfeeding

My baby is 7 months and has always only been breast feed. Before I was pregnant I weighed 105 and I’m 5’2. So already super small. Now that I’m breast feeding I have lost almost 20 pounds. Only thing is about 10 of those was just this month! I have no idea what to do. I hate being this small. My boyfriends family makes comments that I’m anorexic or making myself throw up and that’s DEF not the case nor has it ever been. I hate being this small I gross myself out. I just want to gain weight!! What do I do I feel and look super unhealthy 😣