WIBTA for leaving my boyfriend for searching for teens online?

Im a 33/F and he is 30/M Been together for 3 years. We have a 18 month old baby together. Our sex life is almost non existent. We go literally 4-5 months without having sex at a time. I went through a stage of having to initiate it (which I've never had to do in our relationship) and was met with 'no' or 'what's gotten into you lately?' I felt very rejected. We are also not intimate in other ways. The last time we had sex was 5 weeks ago after we were drunk from a party and again, I initiated. I know my boyfriend watches porn and we've had MANY chats about how I don't like this as it's stopping him from wanting the real thing! Nothing ever changes. So that's a bit of background for you!

I looked through his phone quickly whilst he was busy (I know, I know) and saw he had downloaded telegram and followed a porn chat and on instagram (which he claims he had deleted years ago 🤷🏼‍♀️) he had searched for specific words to lead him to porn (vulgar, throat etc) as well as specific girls he had searched up. And his explore page is just pure girls and porn etc. Now one search amongst all of those listed was an age under 18. This made me feel sick to my stomach that he is purposely seeking out teenagers! I clicked the tag myself and it is what you'd expect. All young teen girls. No wonder he hasn't wanted to touch me for so long. I far from resemble a teenage girl!! Am I over reacting before I kick off and end my relationship?! Because that is exactly how I'm feeling. Why does my 30 year old boyfriend want to look at under 18s 😭

I need help, advice, anything!

Please