How would you react

So my husband and I were arguing tonight (what else is new) we literally have no love or connection anymore. At least it feels that way. The last time we had sex was months ago. I don’t even remember when, probably like 5 months ago and it was a 1 time thing and before that it was the same old story. He’s cheated on me multiple times in horrible ways while we were just dating. But since we’ve been married (2 years) and have a child, I haven’t discovered anything that he’s doing. It’s hard to tell if we’ve fallen out of love or if it’s just because our lives are so stressful, between work and taking care of the home and our child. We all cosleep so there’s no room for intimacy there Anyway tonight we were arguing and I admittedly had a couple drinks and blurted out “I know there’s someone else, and I don’t even care anyway” and his response was a pause and then said “you’re not going to trick me into saying anything”. How would you take that? I’ve checked his phone and haven’t seen anything for once and trust me he is not smart about hiding stuff. But that comment threw me off. Idk if he just said it to make me mad or if it’s true. Yeah I know I should leave him for the past but I chose to forgive and move on and hope that married/parent life would change him. It seems like we are both just so distant and so depressed. Idk how to get out of this hell hole. And this comment tonight didn’t help. How do you know if it’s just difficult marital stuff to navigate through, or if it’s time you separate because there’s nothing left? Please any gentle advice would be appreciated.