Can I get over this lie?

So my boyfriend and I had been dating for a year, and then last summer right when I was about to go to law school he broke up with me. However, the next day he wanted to get back together and said he was sorry, but I needed more time. After a few weeks we were sleeping together again and starting to rekindle thinks. But then we both went out to a club one night, and I was still upset about the breakup I guess and ended up leaving with someone else. The next day I was honest with him about it and said that I was sorry. He forgave me a few days later and we got back together but really has held it over me since, and consistently reminded me that I wasn’t trustworthy. He then broke up with me again before my law school finals in December 🙃 but we got back together a few weeks after and have been together since.

Last week I found out (from looking through his phone aka I have trust issues with him also) that he had sex with a random girl THE SAME NIGHT but he didn’t tell me, while I confessed to him about my mistakes. He kept that secret from me for 8 months, and I’m just so freaked out because what type of person would do that?

He says he’s sorry and that he was trying not to throw our relationship off by telling me. But it just seems crazy since we both hooked up with other people on the same night but he withheld that information while watching me be upset for months and telling me that he wasn’t sure if he could get over what I had done to him.

Should I try to forgive him since our relation has been really great for the past few months? Or is the withholding info a crazy red flag and I should just call it quits.