Attraction Gone

Hello, any advice would be really appreciated!

So I've been with my boyfriend for 3 years now.
We met at uni, and he's my first boyfriend/first person I ever slept with and I'm his first proper girlfriend/second person he ever slept with. I became attracted to him, knowing he wasn't the best looking guy, but I thought he was cool and we started a relationship. By the time we had been together for around 2 years, I realised I wasn't finding him as attractive as I once did. We used to have sex around 2/3 times a week, I think I have a low sex drive, but now he's lucky if we have sex twice a month! I feel as though I no longer fancy him/find him attractive and don't feel the urge to have sex with him because I don't think he's hot anymore. He's not changed the way he looks, it's just I no longer find him attractive.
BUT everything else about him is amazing, he's so caring and kind, funny etc and I am so secure in the relationship. He dotes on me and makes me feel so loved and special. He supports me through all my family issues and drives over to see me all the time (I never go to his house). I spoke to my friend about it before and she said that as long as it doesn't bother me that much, I shouldn't worry. But it does bother me. I don't think it's normal to be in your early 20s and already the lust is gone. He still wants to have sex, but he kind of knows not to really even try it on because it won't happen.
I mentioned to him before that I'm not sure the attraction is there, but he says things like 'I'm sure a lot of girls don't find men attractive' etc. But that's not true, I see people on the street I find attractive and I'm sure his friends girlfriends find their boyfriends attractive! But I just left it there at the time and we carried on as normal.
When we do have sex, it's because I'm thinking 'oh god, it's been ages. I should let him have sex with me', which I feel just isn't right. And sometimes I'll think I want to, but when it gets down to it I'm not feeling it, because I am not attracted to him anymore. When I have sex with him, I do enjoy it because it feels good and I'm not repulsed by him or anything, but I know I would enjoy it much more if it was with someone I fancied. I know a relationship isn't all about looks, and his personality is perfect, but if we are barely having sex, surely it's not right?
I'm so confused what to do now. If it was my choice, I'd just have a sexless relationship with him, but then that's like being friends.
And surely he can't be happy having sex so infrequently. He must feel so unsatisfied and surely deserves someone who will appreciate his looks also and want to have sex with him? I can't see our situation changing as I wouldn't suddenly find him attractive again.
I just can't imagine breaking up with him though because I've become so dependent on him, he provides that security I crave. I can't imagine him not in my life. I only have 2 friends and I barely see them, so he's like a best friend at the same time.
I also know that if we broke up, I'm not going to 'crack on' with other guys. I'm too shy to go on dates etc, so I know I would just be single, which I'm fine with.

I need some advice please on what the best thing to do is. Would it be to break up with him, which would leave us both devastated, but could be the right thing to do? Or do we stay as we are and never mention it again? We have talked about moving in together, but not about marriage or children, as we mutually think it's strange to discuss those things as we never know what could happen.

Thanks

Does he not make you orgasm? Do you get pleasure from sex...

I do get pleasure from it, but I think it's not really due to the person I'm having sex with, more just the act of it!
I find I can be selfish in the bedroom, only doing things which I like - which could be also because I'm not really feeling it.

He is perfect in every other aspect though. We never fight, obviously we had a couple of fights when we first got together and learnt each others personalities etc, but we are so secure. There is a massive amount of trust, honesty, care and love. But I'm worried it's a friendship.

I also find myself feeling slightly embarrassed to let others I know see him, for instance if he meets me at work, I ask him to wait round the corner, saying to him it will be awkward for him to meet my colleagues. I know that is SO shallow of me, and tbh I shouldn't care what others think. I just thought I should mention that. Although it's a minor detail as the relationship is between myself and him.

I spoke with him last night and he was obviously upset and a bit in denial, claiming that most girlfriends probably don't find their boyfriends attractive - which is wrong. It ended with me crying, feeling like I can't handle not being with him.

He brings so much security to my life, as I do have some family/money stress and I always go to him for support and advice. I wanted to live with him potentially in a year. But I can't see myself marrying someone who I don't lust after.

My worry is that it's not his looks, it's me. That I have a low libido naturally and because of stress etc. And that I would do the same thing with another boyfriend.
Does anyone have any similar experiences?