I like to soil my pants
why do you like soiling your pants?
Today I came to the conclusion, that I was overly neglected in having dirty diapers put on me.
I can see that your parents weren't always there for you as a child, but it's important that you realize that deliberately soiling your pants can be unhygienic and unhealthy.  You should take better care of yourself.
Don't you see I'm suffering. I missed not having dirty diapers on me when I was a bit younger.
This is a rather unusual desire that you have, but if it is causing you anguish, then you should go see a therapist.  They will be able to help you feel better, and to get over this impulse.