I cannot control my ejaculation reflex! :(

Hi, I'm new to this community and I would like to ask you all for advice at the moment of controlling the moment of ejaculation and the duration of a sexual intercourse.
It is important to say that I'm 18 years old and I'm not currently having sexual relations with penetration.
But, while masturbating, I can only last so long and I feel I don't have control over it. I'm afraid I will not be able to satisfy my partner when I'm having sex in the future.
What should/could I do? I'd be really thankful for any kind of advice.
Also, let me know if it's not the place to talk about this.
P.D.: excuse me if I don't write perfectly fine, I'm not an English speaker.

 

Hi, thanks for the advice. I started a three months abstain a couple days from today. Is it to much for beginning? I can do it but I'm not sure if it's that much good for me. I mean, at least I'm already feeling better about myself and rewiring my brain about PMO and I hope it'll help me with my problem. I started doing Kegels a loong time ago, but I think the real deal is in my mind.
Should I also abstain from edging? (Masturbating without having orgasms/ejaculating)
...and what about having encounters with my girlfriend? We aren't having sex yet, but we usually masturbate each other a little.
I would really appreciate a response from anyone who knows about this.