Tampons don't fit! Please help?

I'm 15 and I started my period August 2009. I've always worn pads because I've tried to wear tampons but they don't fit in my ! I've even tried to put my finger in my but it doesn't fit and it feels too dry. I've tried putting saliva on my pinkie finger and that fit but I want a tampon to fit and they are too much bigger. I've even tried slim tampons. It hurts too much to try put them in any further than I've tried. Is there anyway I can fix this like by making my l hole bigger? It is really tight and I want it to be looser. I'm scared to have too as I don't want guys to know I'm that tight. Is there a really fast way to make my hole looser? Please help! I'm sick of this! :(