What to do when your boyfriend takes out his previous relationship insecurities out on you?

My boyfriend says he has his friends put in place to tell him when our relationship is becoming toxic, and to get him out of the situation as soon as possible, unlike how long it lasted with his ex, and nobody did anything about it, now I understand he is scared, but it feels like his trust in me and our relationship is not a 100%, cause he also said how he was fine with me having guy friends, but recently after I told him I stopped talking to any guy friends, he mentioned how he was never comfortable with me having guy friends, and just didn't want me to lose anyone because he asked me to, and guy friends are questionable, when I asked him why the sudden change of opinion, he made it out to be me wanting to have guy friends for questioning that, he also asked me not to manipulate him, cause his ex did, I feel why ask me not to if you trust that I won't? And then I was playing around with his cousin, and he got jealous, had an issue with it, and told me for a moment it reminded him of his ex, cause his cousin messed around with his ex, and that I had messed up by doing so even though it was a group thing that he was apart of. Advice kindly?
What to do when your boyfriend takes out his previous relationship insecurities out on you?
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