Getting married

Hey, this isn't pregnancy related or anything!! But just something I wanna know! Say I have bad credit and if my SO and I get married does my credit affect his?? Also for taxes, can we still file separate tax returns even though we are married???? I know these are silly questions! But I feel like my fiancé doesn't wanna marry me and he's using these as excuses😭 we've been together for almost 4 years and are having a second baby any day now, and I feel like he's trying to avoid marriage and Idk why?!! Help please!!!