please help

So basically me and this boy have been going out for about a week or two now and he's really in to it, but I'm not. We got on really well as friends before and I had a MASSIVE crush on him but I'm just not attracted to him at all now. I do t know what to do, I don't wanna ask for a 'break' cuz he's the type of person where anyone would love to go out with him and I know I'll never get him back, but that's just unfair on him and me. Someone please give me some advice 😩