Sir will be along, but in the meantime, here I am, same equipment as you and all. Stress can make orgasming in any form difficult. Have you recently started any medications? Some medications (for instance, Prozac/fluoxetine) can make orgasm delayed or near-impossible. (Ask me how I know this.)

Number one piece of advice is, relax.

Have you hurt yourself? Probably not, but if you're seriously concerned about that possibility, go get a medical exam and be frank with your provider about any way you may have hurt yourself. I mean, are you in pain? If the only problem is you can't get off, damage is not the issue.

Have you done something wrong? I cannot even begin to imagine a "wrong" way to do this, only a not-very-effective way. You may just not have found your own particular "right" way yet. How to Have an Orgasm is one of Sir's most-recommended books for women; he got it for me once, and I'm still not entirely sure why, but it struck me as a good entree into this sort of thing.

If you can, I strongly suggest you invest in a good vibrator. Seriously, I would never have married husband #1 if I'd had even a bad one. Hitachi Magic Wands (NSFW) are universally loved; ignore that funky attachment thing on it, you don't really need it, but then, your personal mileage may vary. If you're worried about portability or stashability, a Pocket Rocket might be more the thing.

I'm sure Sir will have more input, but those are my initial thoughts.