My friend hated porn. Couldn't bear the thought of her DP watching it.
She would dress up (roleplay) did things she didn't necessarily want to do (anal), had sex everyday with him, just so he didn't watch it.
Can you guess what I'm going to say next? She still discovered that he had been watching it!
Him watching it had no reflection on their relationship. He wanted a release and porn use was something he had done since his teens and so it felt natural to him.
Now of course porn can certainly cause problems. Addiction... porn desensitisation. Choosing porn over sex etc. But this doesn't sound like your DP at all.
I found out my DP had watched it. At first I felt the same. I hated the thought that he had pleasured himself to another woman.
But I reminded myself that our sex life is good and that he makes me feel desired. Porn isn't a reflection on me or our sex life.
Don't make it into something it's not. Your DP finds you sexy. He wants to have sex with you. He thinks you're beautiful. Don't compare your worth to a quick sexual video that he watched.
PLEASE speak to a GP. For the sake of your DP, for you, and for your family. 