I need help!!!

So I met the man of my dreams! In October of last year we moved in together! In January I got pregnant with our daughter! I’m 41 and he’s 42. Well on Friday the 20th of this month I get a message from a woman and she told me he’s been cheating on me with her since March of this year! She even sent me all the texts between the two of them! They did sleep together! Now our daughter was born on October 3, 2017 and I don’t know what to do??? I truly love him and I just can’t stop feeling so betrayed! I’m also going through post partum depression! He’s a very good dad to our daughter and I have confronted him about this! He feels really bad! Says he’ll never do it again! Says he’ll show me that he only wants me! I don’t want to raise my baby alone!! What should I do???