Keep in mind that your sexual performance is not totally dependent on using your penis! There are many ways to make a woman orgasm.
A lot of woman report actually prefering oral sex to penetration. That shouldn't stop you from solving your problem with cumming too quickly, but it will certainly take a lot of psychological pressure off you, which may actually make you last longer, if you realize theirs other ways to get her off!
Besides oral sex, using your fingers is another great way to make a woman cum. One great method is to curl your fingers when they are inside her and search for a small bumpy area inside her vagina thats slightly rough to the touch. This is her gspot. If you stimulate it, your hitting the pleasure jackpot so to speak. You can bring woman to new orgasmic heights by stimulating her gspot, wether its with your fingers or your penis.
So don't get too hung up on your sexual performance with penetration, you've got plenty of other tools to get her off with.
BUT REMEMBER! Woman will have the most satisfying orgasms and the most emotionally satisfying sex if you can provide an amazing penetration experience for her. They want to feel you inside them. They want you to be a stud in bed.
So take care of the problem by learning ways to stop embarassing yourself by ejaculating too soon.