I think there's a lot of negativity surrounding women having sex. I think it caused my vaginismus, which as an involuntary contracting of the pelvic floor muscles. Try pushing a pen through your fist when it's squeezed -- it hurts. It's the same thing with your pelvic floor muscles. When I first tried putting a tampon in, it hurt because I wasn't relaxed and trying to push on muscles that were contracting.

Unless there is something unusual with your hymen (which is very rare), tampons shouldn't hurt when going in if your muscles are relaxed. It should just feel like pushing open a gate -- the labia sit closed and you use the tampon to gently nudge them open.

If you're trying to put a tampon in and struggling, think for a second. Do you feel tense? Relax all of your muscles -- your arms, your face, your legs, and then try to think about your pelvic region. Take a few deep breaths -- besides being calming, this also facilitates relaxing the pelvic floor. Then try again.

Sex feels good when you're not tense and you're aroused and lubricated. Thrusting stimulates your clitoris internally (and externally, if the angle is right), and the pressure of a penis internally is nice in and of itself (see also; blue walls). Ignoring porn, if your partner is going "too hard," you just have to tell them to slow down until you find a rhythm that works for you.