Sad and confused… in Life Lessons

I need some help… my mother in law and sister in law are always pestering me to have a baby. I have many health issues and don’t know if I can even have kids. So I’ve tried to not think about it too much and just convince myself that I don’t want/need them. My husband knows that I feel this way and is very compassionate towards me. He knows that his mother and sisters comments about kids really bother me - but his mom told him that’s she’s just joking and that that’s the only thing she can talk to me about because I’m scary and intimidating and she thinks I don’t like her.. he says I need to not get my feelings hurt over it.. is he right? Am I over reacting? Do I need to just quit letting it bother me? He tells me it’s just a mental thing and I just need to “turn off the worrying” but I don’t know how.. it’s just how my brain is.. is that normal? Can most people turn off the worrying? My mother in law and sister in law don’t like me (more stories in other entries) but my mother in law always tells my husband that I’m the one that don’t like them.. please help…