It is very unlikely you have caused any harm, and your vagina is probably plenty "tight". How would you OR he know how "tight" a vagina is supposed to be anyway, if you're both virgins?

It will be fine,, after all he has nothing to compare to right?

You also go back, it gets loose and tighter all the time...I recommend doing exercises to help tighten it up a little if you are concerned with it. They do work.

I can fit two fingers into myself, and this has been done through experimentation. Is that normal?

Yes, of course.

The vagina is a very flexable area... it is designed to fit a baby head thru it as well as a variety of penis sizes you do not want to be too tight other wise intercourse will be uncomfortable. If you are worried about it, look up Kegel excersises. They are good for women and men. they strenghen the pelvic wall reduce urinary incotinence, make it easier for you to controll your muscles "down there" and make intercorse more interesting when you can "squeeze" him.

my mother used to have a bumber sticker that read " Women unite, keep it tight; Go Kegel!"

No matter how improperly you used a tampon, it's not going to stretch out your vagina. Even years of sex will not stretch out your vagina. Your vagina is a stretchy thing. It's made to stretch and bounce right back. So sex, tampons, and fingers are not going to stretch it out. Only a baby, or baby sized objects if you're kinky, would stretch out your vagina permanently.

Using two fingers is perfectly normal. That is in no way related to virginity.