If you feel your tampon is hitting a wall and wondering, ‘why does it hurt to put a tampon in?’ then it could be because you’re pushing the tampon in the wrong direction or at a wrong angle. Trying to insert it in a straight up, instead of an angle will not make it go deep enough. Consider laying on your back and aiming for the floor to get a feel for correct insertion
It’s normal to feel some pressure when inserting a tampon for the first time. But with a few attempts, you should be able to insert it without it hurting you. If it is still hurting, then you’re not inserting it properly.
When used correctly, you will hardly feel the tampon. Or even if you do feel its presence, it shouldn’t be painful or uncomfortable for the duration that you’ve worn it.