I don't have feelings for my boyfriend anymore but he really loves me and i don't know what to do, help?

Well, i really did love him before but realized i wasn't really physically attracted to him. Despite that, I kept up our relationship because he treats me extremely well and is a nice guy. Recently, however, I've stopped having those same feelings and I know I don't love him anymore. He loves me though... and every time he tells me that he does, I get a guilty feeling and it makes me so sad... I'm not happy and I hate pretending our relationship is perfectly fine, but I just can't bring myself to hurt him like that by telling him how I feel... If I did break up with him, I'd want to stay friends but I know that'd be too hard for him. I realize how unfair it is of me to make him think I still feel the same way, but I honestly, really don't want to hurt him, so it seems, although I am so unhappy, keeping him happy is all that matters... I really don't have a clue what to do, I just feel trapped and lost. Then there's another problem, whilst I've been with him I've met so many new people and made new friends and I love them, but I feel as though if I hurt my boyfriend or we break up, then I'll most likely lose all contact I have with them, and I really don't want to because that will kill me too so technically I will be unhappy whatever I do... I know it's a selfish reason to stay with him but I don't know what the best thing is to do, so I just need someone, anyone to give me some advice. This is a frustrating, awful situation, I just need some friendly help if anyone can... And just in case anyone feels the need to tell me, yes I'm aware people are worse off and have bigger problems than me, but I'd really like some help. Sorry for rambling on. Thanks guys, any help will be much appreciated x