Question for girls only please!!?

Okay, so im 15 years old, and iv had my period for a year now. I hate using pads there gross and uncomfortable, so I tried using a tampon which my mom told me that im "not allowed" but I can decide whats more comfortable for my body. So the problem with all this is that I couldn't get it in!! I tried a cardboard applicator and it sucked so i tried a plastic one, which was a lot better but i still couldnt get it in, i feel really dumb cause i dont know how:P And yes i know theres instructions in the box, but it doesnt really help. So I was just wondering what am I dong wrong? I just can't seem to get it in.