My boyfriend is having trouble climaxing

I got on the depo shot 3 months ago and me and my boyfriend have been having great sex and he’s been able to finish every time. About 3 weeks ago I switched to an IUD and during the switch we agreed not to have sex so we won’t worry about an accident. During that time we agreed we could masturbate if we wanted to. We are having sex again but my boyfriend is having trouble finishing and it’s making him feel bad. I’m doing everything I can to get him to climax but he’s not. Is there anything I can do to help him get there?