Stress related question ?

So i hate my mil. Shes soooo fake towards me and only texts me to ask about my husband. Nothing about me or baby ever. My husband and I both dont like her just from stuff she’s did/said to me in the past. Long story short we have to go over there tomorrow and haven’t been in about 6 months. The thought of going over there peaks my anxiety and makes me not even able to sleep. Can stress cause preterm labor? After we get it over with I’m fine but just right before we go over there and while we are there I’m in constant anxiety and I’m upset. I’m 23 weeks this week and I wish I could just calm down but her presence just eats at me.