Plenty of lube and a thickish condom worked for me.
What do you do during sex? Is it full on from the off? If so, try going slower. Same for mastubations, don't just grab it and go until you're done, use a lighter touch, take yourself to the edge and stop until it subsides. Same for sex, instead of just stopping you can use these little breaks to change position, which changes your sensations and helps last longer. Mastubating more regularly could help too?
Pretty much full on from the off as I seem to get so excited I shoot my load sometimes even during foreplay my just has to stroke my penis and I cum,I just seem really sensitive and so turned on I can't contain myself.
I would recommend you think about other ways to please her than just intercourse such as oral sex and frankly using toys ON her. If she has already orgasmed a couple fo times before you get inside her that should result in a very satisfying encounter, even if you go super fast.
I also think the more you stress aobut this that you are getting in your own head an possibly making it worse. I dont have any specific suggestions to help with that but mental state is very important as well.