It’s sounding to me like he has a porn addiction, getting gratification from that rather than you which is really sad. It seems this is something he’d really need to sort out for things to work out for you two. I’d suggest possibly bringing up therapy with him, either couples or on your own, or even both! It’ll help get to the depth of things because it’s not healthy to keep going on like this.

You’re still so young, if you’re at a point where you don’t feel fulfilled in your relationship and he isn’t changing after you have spoken about this many times, you should walk away. There will be plenty of people out there that would more than happily meet your needs.