20 weeks now alone!

Amy
I'm 21 with a 2 year old daughter from a previous relationship which we had to flee from as he was violent ... He has nothing to do with us and neither do hi family! Almost a year ago the most perfect man came into our lives cared for us and took my daughter on as his own!he was the best father I could imagine .. She calls him daddy! We decided to have another baby together to add to our 'perfect' family.... Now I'm 20 weeks pregnant he has decided to tell me he's unhappy in our relationship (this has come as a total shock as we were fine! An argument which any relationship would have normally was apparently his reason for leaving.. Oh and we aren't right for eachother anymore... Apparently we have true to fix things too many times) has anyone else been left whilst pregnant? How do u deal with it ? What sort of a man ups and goes right when I need him the most?!