I struggle to cum and don't feel much sensation during oral sex?

I'm a 27 year old guy. I get almost instant boners but the problem is that I've never felt mind melting pleasure from oral sex especially. Two days ago I was playing around with a girl, she gave me a blowj and a handj for almost an hour and i was not able to cum. Not sure if I have a less sensitive penis but I know they feel bad not making me cum and then I feel bad for that. I tried concentrating while she was at it but nothing.