Am I overreacting?

Hi guys, (post will be tmi). I’m a first time mum in my late teens my baby is 6 months old I recently had to stop my baby’s dad from seeing her as he’s constantly putting drugs, drink and friends over his own baby and only makes time for her when it’s convenient for him but had said to him once he realised he should be putting her first over them things he can start seeing her.

What concerns me is that I recently got showed proof of how he treated his past relationship. He had abused and done other things to her. I did not know any of this before I had gotten with him and the whole time me and him was together he was not like this with me and trusted him as well as with the baby but seeing pictures of what he done before has broke the trust completely and concerned for my baby’s safety incase he could loose control and turn into his old self, am I over reacting? As I feel like I shouldn’t allow him to have her by himself.