Excessive wiping and Anal tears

Hello all,
I have had the same problem for as long as I can remember. Whenever I have a bowel movement, I have to wipe over and over before the toilet paper comes up clean. Often this excessive (but necessary) wiping causes tears on my anus, which bleed and reopen the next time I go to the bathroom, making it very painful to go. Then I have to wipe and the whole process starts over again. when I examine myself in a mirror (not easy to do!), I can see some large and swollen wrinkles, and small tears, and these correspond to the very painful areas.

I have found that using a bidet is the only thing that will remove the need for excessive wiping, and thus resolve the bleeding issue. Minor anal douching when I start to feel raw and sore also helps to alleviate the pain.

I feel I have found a solution but I still don't understand the problem. Why does it take so much wiping to get clean? I don't feel like I'm "doing it wrong", or using too much pressure, as it is the number of times I wipe, not how hard I press, that hurts me. I don't have any leakage between bowel movements, I go regularly and my poo seems healthy. I don't have any other abnormal digestive symptoms, and this is a very persistent and consistent problem. Does anyone know what might cause this?

As for my diet, I have been vegetarian for about 7 years, and eat very little dairy and almost no eggs. Becoming vegetarian did not affect this issue at all. I eat a lot of rice, cereal, and noodles, as well as tofu. I am currently living in a country where fresh fruits and most vegetables are too expensive to eat daily, but I do what I can. I have been underweight most of my life, but have recently gained enough to be in a normal range.

Any guesses would be appreciated, thank you!