Can’t finish

So I’ve been with my boyfriend for 6 months now and a lot of stuff has happened in that time but the past few weeks when we have sex I don’t finish and he will do everything he can to help but nothing has been working so I don’t know if it’s me or him or both or what but it makes me mad because I feel like I’m getting close and then nothing ever happens and my boyfriend is getting depressed because he feels like he isn’t doing something right I just don’t understand I’m in love with him and I’m attracted to him I just don’t understand why that’s been happening or in this case not happening sad😔