what should I say to him because I dont wanna hurt him?

It would be selfish for him to expect you to sacrifice your own solace for the sake of his. It’s always going to be hard to tell somebody who cares about you that you don’t feel the same way.

No one should ever feel guilty about being honest. Allowing this person to delude himself into thinking that the two of you have a romantic future ahead of you could do him more harm than good. Sex should be out of the question seeing as the two of you are on completely different pages. Being intimate with somebody who does not share your level of affection is heartbreaking and you don’t know it until it’s too late.

Letting yourself fall victim to your own symapthy will only make this matter worse. Tell him that despite how flattered you are that he feels this way about you and despite the fact that you do care about him, you can’t take this leap of faith. We all deserve to be happy and nobody has the right to expect their own happiness at the expense of your own. Be brave and stand up for yourself. Do it for yourself and do it for him… Be open and despite how difficult it may be initially; I’m sure it will be all for the best.

Sorry that no one managed to get to your question sooner. Good luck (should you still need it) :)!