I can't make my boyfriend cum

I have been with my boyfriend 3 years and just recently I have been unable to make him cum with blow jobs and hand jobs. He tells me he enjoys it but I need to carry on for longer, it has been reaching the 35 minute mark when I just give up. I am aware this is a very female oriented app but if anyone has any tips on how they make there boyfriend cum it would be appreciated. It's making me feel a bit shitty that I can't please him