What exactly is "vaginismus?" Can this situation be solved?

I would prefer receiving answers from women who have had this problem.

It can totally be fixed. It's an involuntary seizing up of the muscles in the vagina, so sex cannot be had, or it can but only very painfully. The cure is to get "dilators" that progressively teach you to relax and loosen the muscles to admit things into it. There's a lot of information here: http://www.vaginismus.com/
It's pretty common, which is why there's so much about it.

I had an answer for you, but since you only prefer answers from women who have ''had it'' good luck- it's rare

It's a mental disorder that causes the vagina to clamp up. It was discovered years ago. It's more common in women who have a lot of children. They are afraid to have more, so when their husbands try to get intimate, they clamp up tighter than tar on a roof. When they go to the doctor, they open up. They may not even be aware that they are doing it.

Yes, it can be solved, just like any mental condition. Seek therapy. Or get on an IUD, which is the most effective of all the birth control methods, other than abstinance.

Never had the problem personally, but vaginismus is a condition where the PC (pubococcygeus) muscle tightens up so that the walls of the vagina are tightly squeezed together. This makes inserting things into the vagina *very* painful, if not impossible. The muscle clench is a subconscious reflex, like blinking, rather than a conscious squeezing, which is what everybody keeps ranting on about with Kegel exercises. It's not all that unusual, something like 10% of women will have it at some point.

It's quite treatable, usually with counseling, sometimes with physical treatments. The problem is that it tends to be self-perpetuating... a woman has painful sex/insertion of a tampon because of vaginismus, and so she stores that up in her mind and the next time she is inclined to repeat the experience, her subconscious spits out "OMG NO PAIN OW!" and the clench begins again.

I've been married for three months now,i hadn't had sex before.and on my wedding night (i wasn't scared or anything ) but the initial pain i felt upon the attempted penetration made me seize up n made it impossible to go any further, my husband just thought i was scared but it really was involuntary n every time we tried after that it was just too pain full for me Cos my internal muscles would totally tense up,the sad thing was he'd been planning our honeymoon for a year and we didn't do anything the whole time we were away.....ANYWAY we took it really REALLY slowly and GENTLY, n every time he'd go in a little further and pulse(sorry for being graphic)
eventually after a month or so things finally worked out.
i know some women have it a lot more severe than i did, but there is a cure n some women actually opt for surgery which by the way can leave internal scarred tissue ... hope i helped....