My heart really hurts please help💔

So me and bf been together for three years and TTC and I thought we were heading to marriage soon I never thought he'd be doing anything behind my back... Well three days ago I find out on his bf that his been searching this girl name Jessica Reyes idk who she is but in his FB search bar it he had like different profiles like his searching hard for this girl. Honestly it hurts me cuz I dont seek other ppl I really thought his the one to not ever hurt me since he knows before him I was in a mental and physical abusive relationshit. So idk how to take this what do u girls think?? I always have put him first in everything n to see this it hurts. When I told him he tried to lie n say it was his cuzin clearly I ain't stupid so I got upset till he told me the truth said he was just looking for this girl n that he didn't talk to none of them .. what hurts me is why is he searching so hard for Jessica Reyes... He won't tell me who she is .. he just says she don't matter that he loves me n he is always with me but I hate being lie It hurts to know his been doing this behind my back. I don't have friends or anyone to talk to I just had to let this out I'm hurt. Please no rude comments. Thank you😢💔😞😖