Great and fulfilling sex can and should be a lot more varied than just fucking. Spend more time on initial foreplay and oral - a lot more time. Aim to assist one or two orgasms for her prior to intercourse. You aim for more than one orgasm - go back to oral and foreplay for her while you regroup.
Switch up intercourse with oral if it gets too intense for you.
When fucking, if you feel the onset of orgasm penetrate deeply and hold that position for a moment until sensation subsides or short movements when penetrated deeply. Vaginal muscles are stronger near the opening which will increase the sensations on the head of your penis if you are doing long strokes. There is less sensation for you if those muscles are pulsing and constricting further down on the base of your penis shaft. When you feel in control again you can revert back to longer strokes if that is what you both want.
Grinding and bumping while deep may be pleasurable for her - try her grinding while on top of you while you remain deep.
You can hold off an imminent orgasm by tightly squeezing or pinching with your thumb and forefinger on the base of your penis.
There are delay sprays, I have no experience with these to offer brand suggestions. I have heard that it is possible for you to use this without impacting your partners sensations. All online adult shops should sell those products.
! I second this !