I used to have a very sharp pain when I used the bathroom to the point where I would hold it in. I dreaded using the bathroom every morning, no matter how much water or fiber I got during the day. I did some research and realized I most likely had an anal fissure.
What worked for me and helped me heal is Fleet Glycerine LIQUID Suppositories. Not the waxy crayon like ones, the liquid ones. They come in a pack of four for around $5 or so. I ordered a bunch online from a vitamin shop.
They are liquid capsule things with a bright orange cap. When you feel the urge to go or even before that, follow the simple directions. They help make everything much more smooth and easy.
I had to use them every day for a while, and now I only use them occasionally. I still have some pain, but it's not nearly as bad. If I drink a lot of water and eat raw veggies and fruits sometimes it's minimal.
It's a world of difference!