Post-pregnancy dilemma

hello everyone! This is my first ever post and I really need an advice on this one.
5 months ago I gave birth to a wonderful baby boy. And since my delivery, our (my husband and I) sex life has never been the same again. He stopped doing the things we usually did on bed before. The excitement was gone. We would only **** when he's drunk and never when he's sober. And it would always start with a massage as I try to arouse him but it's been hard to make his penis get up for a longer time or to even make him cum. He doesn't touch me anymore. He's no longer as sweet as before. As for me, I don't feel so horny anymore. Sometimes I would catch him watching porn and he hides it from me. Also I would check the history on our laptop and some of it has been deleted. He's hiding stuff from me, maybe he's watching porn or talking to other girls. And it makes me think that maybe the reason why he's not satisfied with me anymore is because he's setting his standards on the porn he's watching or on those girls he's talking with. I'm scared that one day he will **** somebody else and cheat on me. What do I do? How do I get back the intimacy we once had Help!:(:(:(