Found out boyfriend talked bad about me when we were separated - how to cope and find out the truth?

I found out that during a separation, my boyfriend had been going around talking bad about me and also trying to hit up girls from the past on Facebook. Most these girls ignored him and didn't respond. A couple did though. The one was sexual based. She was into like sub/dom stuff and she was telling him she could teach him things and he said he was open to learning new stuff. It died quickly and nothing else was said and I have no idea if they ever met up to really do anything or not.

The second one was more hurtful. He started off by messaging her apologizing for "before" and saying he understood if she didn't want to hear from him or talk to him. She replied. They started to talk and he told her he was in a bad relationship and finally got out of it aka ours. It hurt me to see he considered the relationship a "bad one" when I treated him like a king. He told her I was "toxic". He told her he had missed talking to her. She is many miles away in another state now and he even said he could come to her state to visit. This was really hurtful and made me feel like he still had feelings for her.

They also didn't talk long though and he stopped trying to message other girls really quick and I noticed when he stopped trying to message others is when he started to really get more invested in me again. The texts picked up and he started wanting me back.

I wonder if he really does love me or if he just took me back because no one else wanted him. I understand that during a break up, you can seek sympathy from others (what he was doing) and that you can say things you don't mean.

He was the reason the relationship ended before. He got really mad over something stupid and just blew up and left. He was really mean to me and got verbally abusive. Yet he was blaming me for it.

I also saw where he told a guy friend I was "crazy" and that hurt too because no I'm not.

I don't know if he is genuine about us being together now.

Updates
1 y
Him immediately trying to hit up other girls after we split was hurtful and insulting. I also didn't like the sexual one because he is not too experienced which I knew already, but he doesn't mention US exploring anything or him wanting to learn anything. He had told this chick he was down for learning new things. Wtf? No telling if anything happened, but why wouldn't he have mentioned wanting to learn anything else with ME? He still hasn't even though we're back together.
Updates
1 y
He told me I satisfy him sexually and stuff and we do have good sex but why wouldn't he want to learn stuff with ME? And how could he have been messaging other girls so fast? Was he just depressed and seeking comfort/sympathy? Or was he just not in love with me? He acted like it. He acts like he is now too. But now I wonder if he is legit. I wonder if he can be trusted. I wonder if he still has feelings for that one girl out of state and is just with me because I'm local. How can I get answers?
Found out boyfriend talked bad about me when we were separated - how to cope and find out the truth?
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