Has anyone else ever dealt with this?

My husband and I (both 21) have had GREAT sex all the time, until about the past 6 months. It started out as just him not eating me out anymore, we would still have sex though. I was bothered by maybe if there was a smell or something but he denied all of it, I would try to get him to do it RIGHT after I showered, still nothing. He always claimed he "wasn't in the mood" but I always thought there was something wrong "down there" I would beg him to at least try it while we are having sex only for a couple seconds, maybe that would put him in the mood and he got so damn AGAINST it that I don't even ask anymore now I'm so psychologically fucked and spend at least 20 min in the shower everyday washing JUST down there and then continue my shower. Now more recently we have stopped having sex. Maybe once every two weeks IF I'm lucky. And every time that does happen, it's always me on top, he lays there. I asked him to do different positions and he won't. Not in the mood. I feel used, and unappreciated, unattractive, because all I can think about is how we are 21, age isn't a factor in fact I feel like guys his age are ALWAYS trying to have sex. I looked through his internet history on his phone, no porn no anything. Until two days ago I looked more into his phone and saw his google chrome app. Clicked on that...and EVERYYYY DAY literally everyday dozens of porn videos in his history. So I know for a fact he is often "in the mood" so what is it that's making him choose porn as an outlet instead of me?? 😔 I feel like a horrible wife because I somehow can't make my man attracted to me more than the girls in the videos. I wouldn't say I'm ugly, I have long blonde hair and he prefers blondes, I have a butt, and I'm 5'7" and only 140 pounds, he prefers smaller women. So I'm just confused as to WTF is going on?? And it's straight porn he watches so it's not like he's secretly gay. I'm at such a loss. And I've asked him all this, am I unattractive, do I need to lose some more weight, am I doing it wrong in bed, I've openly asked him all these questions with promise of no retaliation, and he denies all of it, says I'm beautiful, says nothing is wrong, he just prefers watching porn over having sex. Is he just lazy?? This is driving me nuts and makes me sad because I am human, I do want physical affection but I'm not getting it from the one I love and I would never cheat so I always feel less than or don't believe him when he says I'm fine. Ugh I'm a mess😔 has this ever happened to anyone ?