Ew. LW, lying to someone (even by omission!) about your relationship status when you start dating is a big lie. It serves no other purpose other than to manipulate. He’s almost surely lying to his wife, too. He’s gross.
I literally never asked anyone I was newly dating if they were in a relationship — I don’t think that’s the norm, so I disagree with that advice above. However, you can pay attention to any red flags and things that don’t add up. You don’t mention how you eventually found out he’s married.
Anyway, you need to cut this guy off completely. You get that hit of dopamine when he reaches out and “wants” you — been there, it feels good! Then there’s the low that follows. Rinse, repeat. You have to put an end to the cycle. The person who hurt you cannot give you closure; you don’t need him to validate that he hurt you when you KNOW he did. So block his number. Block him on social. Remind yourself as many times as you need that you deserve better than this.
I’ve not been in this situation, but I did once find a boyfriend of a year online dating and learned he had a whole-ass other girlfriend. Which I bring up, despite how different it is, because it’s the one time in dating that I was lied to and manipulated in a big way. I was devastated, it was very painful. The acute sting of the disrespect lasted for a long time. I felt like I had no idea who I’d been dating because the man I knew him to be would’ve NEVER done that — I felt insane after we broke up because reality and the lies he was feeding me were so mismatched and I trusted him — so I also questioned who I’d even been dating. He’s the one person I feel like I fell in love with the fantasy he sold me. Anyway, it took some therapy to understand how I’d ended up in that mess (e.g., red flags I’d overlooked early on), why I ate that guy’s fantasy self up, and heal and move on to look for a healthy love. HIGHLY recommend you look into therapy as well.