Dating somebody who’s been with everybody

So I’ve been seeing a guy for 2 months now, he has been divorced for 2 years and has a son. He is the best dad, is good looking, mature with his ex, good job, nice house and the sweetest guy I’ve ever been with. We’ve been inseparable since the day we met, hanging out every weekend he doesn’t have his son, eating dinner together almost every night, I’ve met his friends, parents, we go to the gym together, he makes plans weeks in advance, etc.

The issue... I’m pretty sure after his divorce he went buck wild with women. He has tons of girls always liking his pictures, adding him on FB, but He posts photos of me/tags me in stuff, i’ve seen his inbox and there’s nothing suspicious... This one girl reacted to one of his posts with me weeks ago with a “laughing” face. I ignored it. Yesterday on a post he made about us for valentine’s, she did it again and commented saying something really rude and I showed him and he unfriended her. Today she posted another rude comment on the same post, so I said “who are you? You don’t even know me.” To which she responded “I’m the best friend of the girl he calls for booty he called her just last week” and “you said your gf was a friend” and I immediately wanted to throw up.

Granted this girl and her best friend both look like trouble makers and obviously love drama... he publicly called her out saying it wasn’t true, she was crazy, etc. he told me the girl is someone he slept with before me and that he hasn’t been with anyone at all except me since we met. I have no reason not to believe him, like I said he’s with me all the time... when would he have time to do that? I even keep stuff at his house.. Plus why would he be introducing me to family and friends and posting about me if he was worried about another girl? I do trust him and I even asked the girl privately for proof and she couldn’t give me any. I just hate that it made me look stupid publicly and I worry that there’s gonna be more girls like this in the future since he obviously likes them crazy.

I feel different about him, like this could actually work and we could be great together. I’m just so insecure and stress so much. After being cheated on many times before, how do I put my mind to rest about this? And how do I handle this in the future? Do you think his actions towards me say long term? I’m just emotional and overwhelmed and I hate feeling like I’m clueless