Lost our spark...i feel uncomfortable in my own skin

I'm upset ladies and don't know what to do...for the past few months sex between my boyfriend and I has been decreasing. We live together so i chalked it up to that... just seeing each other everyday and having less sex is normal, right? Well last night we tried to have sex and it just felt so boring, foreplay was good...but literally as soon as he goes in me, he loses his hard. Like all the way. It we tried foreplay again...same thing. After 3 failed attempts and wasted condoms, i gave up. My boyfriend felt so bad, he told me it's not me and he just doesn't know why he can't keep his hard.

I just COULDN'T help but feel so ugly and uncomfortable naked. I just wanted to put my clothes on crawl under the covers and cry. This has happened a few times in the past, but I don't know last night was different. I just felt such a disconnect between us. Like we were even using lube and toys to try to help and nothing helped. we just didn't feel turned on by each other. I didn't even want him holding me or kissing me after because i just felt so unattractive and...... turned off😭 what can we do to fix this? I'm feeling so insecure.

We are 23. live together 2 years now. No he is 100% not cheating, that's not even a thought in my mind. Besides sex, our relationship is wonderful and going uphill, but last night felt like the intimate part of our relationship fell apart. He is being so nice to me trying to make me feel better but i don't. At all