Currently having a really hard time with my first pregnancy. I'm 18 weeks pregnant... My fiance has…

Currently having a really hard time with my first pregnancy. I'm 18 weeks pregnant... My fiance has reached an all time low with a mid life crisis that hit at the best of times... Out of pain, anger and fear he recently told me I ruined his life and I'm going to be a horrible mother. Everyone (besides my loving sister) has abandoned me... I feel completely alone and extremely terrified. I have no idea what to do.