Heartbrokenđź’”

I'm totally lost.. 
Me and my partner have been trying for a baby for over a year, gone through losses and finally were pregnant again and 12 weeks, longest being pregnant. 
Only to find out that he's done it again. He talks to girls on Facebook about meeting them and wanted to have sex with them so badly and that me and him are preactially over, when at home we are the happiest couple ever. 
He's done this to me before but now I'm in a different situation. I'm having his baby and I love him so much. I'm just lost I don't know what to do. I don't understand why I deserve all this crap from him.Â