Is this normal?

I’ve never orgasmed and I’m 17 years old. So this is about to get freaky but I need answers because I feel very lost. I don’t have any sex toys and I know I can use my fingers BUT I sometimes use tampons and try to fuck myself with it. And at first it feels good but then I feel a loss of sensation. Almost like it’s too small to feel inside me. Why is this?? Should I be using my fingers instead?? Because I know my pussy isn’t loose since I’ve never endured any physical changes towards it. But I’m lost and I’m starting to worry I won’t feel pleasure when I have sex. Or am I doing something wrong.