Yes you may need to use a bigger tampon and change it more frequently. I would also recommend if you use tampons also use a pantyliner, that way if leaks do occur they are not on your underwear.
Also, like Kim said if you find tampons to always be uncomfortable, use pads. If you need help with putting them in correctly ask your mother or another woman to help you.
if your blood is leaking through a tampon either its too small or your not changing it enough.
if you cant put a tampon it correctly and its alway uncomfortable, maybe you should just use pads