I'm 27 and have been with my husband for 8 1/2 years. We've had sex more times than I can count. But I'm not sure if I have ever had an orgasm. Last night we were messing around and used some stuff called orgasmix. It felt great but I never felt like a release like when a guy has one and then they're done. Put it this way I was sqwirming all over but I never felt it climax then kind of die down.
What am I missing here?

Near miss. You were close to orgasm but you miss it. You shouldn't have stop you were very close. I'm a guy of 36yrs, been with my girlfriend for 15yrs now with two kids I perfectly know what I'm talking about.Orgasm is just a complete self satisfaction. What you achieved is pre orgasm, a few seconds more you would have achieve it and you should have felt like releasing something. My girlfried gets more slippery after orgasm, some may release load of juice and some may release nothing at all, but the feeling of self satisfaction should be there.

I don't think you are missing anything it's just that your partner should know you more and be patient. Don't rush, take you time, good amount of foreplay is necessary and talk to him, advice him that during sex when you are gasping for breath and heaving your pelvis you are on the verge of orgasm and he should not stop.

Try reading my answer to monica about orgasm.

Have you tried lots of foreplay before sex? And don't get too worried about not having one. Some times thinking too much is a bad thing, especially during sex.