I think all of what’s beeing said above is good advice and good plans of action to put into motion. Limiting porn and frequency of masturbation for fun will help, continuing with pe will help in many other facets and when it comes time to “play” with a mate you’ll be ready to go. As said above ejaculation is still important, and I would never refrain anyone from doing it twice a week (when not being done through sexual encounters).
Maybe you’re focusing to much on yourself, your thinking too much in the heat of the moment. Your tricking yourself into lossing the connection you have with the person in that moment. Which is similar to why some people have ED, when your thinking or expecting to much, the pressure or expectations you’ve placed on yourself are causing you to not perform optimally. Enjoy the moment, explore her body and take it all in. Make a connection with the person and focus on her enjoyment, if she’s enjoying the moment, you will be to if that connection is there.
Honestly for myself, getting a girl all worked up and causing her pleasure in turn gets me going. What ever works for you is the key. Wish you all the best with this and your pe career :) .