Me and my boyfriend

Me and boyfriend have been dating for 2 years and 7 months, I am 14 and he is 15. We have had sex a lot of times any changes we can get. But for some reason I don’t understand when we have phone sex I can’t orgasm, it’s really weird I use to be able to when we first started doing stuff and even before that but I can’t do it now and all the internet says is “slow down, lead yourself into it. Don’t rush. Take your time, and tease yourself.” But I have done all of that and I get the after feeling but I don’t get the in the moment feeling. And it’s really stressful because my boyfriend always gets to finish.

Please help!