I think I'm giving up😔

I think I'm giving up on TTC things are really rough between my partner and I in the last past weeks I found out he's still sleeping with the mother of his child and I'm devastated...every month I start my period he's upset that I didn't get pregnant by him he wants another kid as much as I do but I don't want to deal with him sleeping with someone else a friend told me that's part of life and that babysdad and babysmoms will always sleep together no matter who they are with and I just feel like that's bullshit I think I'll wait on the baby thing and is thinking about walking away all together we been together 5yrs my heart hurt😢