My boyfriend’s porn is causing relationship problems.

Me and my boyfriend are having a baby soon. We’re both young only 18. For more background info me and him have a pretty good relationship(no relationship is absolutely perfect). We’re with each other almost everyday, throughout the whole day. I never felt like it was right for me to look through his phone but my body is always in fight or flight mode. Every time I’ve looked through his phone I’ve found some sort of pornography or only fans women. I’m the type that likes to talk about things that I’m bothered by and every time I find something and bring it up he always says the same thing. “I’m just curious”, I had a bad dream and decided to go through it again this morning and found porn in his watch history on X. That’s all that was in his watch history. I woke him up from being emotional and he sweet talked me and kept asking what he did. When I told him he said he didn’t know what I was talking about so I showed him and he had nothing to say, per usual. I ask simple question to try and understand why he even does it and he can never answer because “he doesn’t know what to say”. He told me he just gets curious and doesn’t ever jerk off to anything. This was the third time I’ve looked through his phone. So in the last 3 months this is what has been happening behind my back. I just want answers so I can understand and help. I express to him every time how it affects me. I ask him why he even puts us in this situation and how it not only affects me but our baby that’s growing in me. I’m in my second trimester, all I want is for him to get better and stop doing it. I express that it’s not only about me but about him and how unhealthy it is religiously to feed his body and eyes with those things. He tells me he knows and that he’s thankful I care. But I’m never given any answers to get to the bottom of this problem to help or solve it. I have enough support from family but all I want is for him to get better because I do truly care about him and love him. Please be completely honest, I just want answers. (Also, I would take pictures on my phone of what he was searching and watching and he’s deleted everything because he doesn’t want me to keep looking at them because it’ll just make me mad). Now I don’t know whether to believe he’s actually quit or if he’s just gotten better at hiding it.