After birth

I gave birth 16 months ago and I’m still having pain as I feel tighter down there. I used to wear small size Diva cup or regular size tampons and now tampons hurt and I can’t fit Diva cup in my vg. I also had couple of check up and it hurt so bad I wanted to scream and tears coming out. But my ob thinks all normal, she says not to worry. I had assumption it gets wider not tighter!?

PS. I did tear little during giving birth. Maybe that’s the reason. But kinda feels like it hurts when tampon is inside. So that should be different.