First things first, trying is _always_ planning to fail.
So squeezing the butt causes you to come faster? Don’t do it.. Besides it’s quite logical to accelerate unto the PONR when you squeeze your butt. Think about where your dick’s head will be inside a vagina when you do that.. Better chance for babies! ;)
Aaaanyways:
The main problem is that people tend to get caught up in the problems they created in their mind.
Instead of simply changing what they created to begin with, they start struggling with themselves and fight what they trained their mind to do to begin with.
Make a truthful and honest decision right here, right now, only with yourself (or to someone you trust, if that helps you to stick to the decision).
Let your decision be something along the lines of: From now on I’ll stop judging myself ever, especially when I get what I was thinking about happening for the longest time (and no, it doesn’t matter if you want that thing you focus upon or not. The focus of your attention is where it’s at).
Then once you’ve made this decision keep it as good as you can in any given moment.
And for the dick part of your situation I would suggest to aim for something along the lines of: “Ah, let’s see how great I can feel when I just play with myself (or her).”
Don’t make orgasm or cumming or even the good feeling that ensues your goal. Instead make finding out how much better you can feel on your way to orgasm (not necessarily cumming) every time you have sex (be it with yourself or someone else).
The saying “The path is the goal.” comes to my mind here ;)
And let me assure you this: When you start to concentrate _only_ on how long you can ever more fun on the path, the goal will be much less impressive.. if you even want to go there.
Ys
P.S: No worries, you can still ejaculate if you wish. It’s basic human programming after all. But you don’t have to go there if you don’t want to.