Some people are not equipped to be parents for one reason or another, but end up with kids they are not mature or emotionally ready for, thus, they do not have any parenting skills or the desire to have them. The kids then are targets for their miserable existence. Some parents just "practice" on their kids and don't really get anything right till they have grandkids to spoil, and some never change. We just need to pray for them because they must be very unhappy souls.
When you don't have parents to share with, there are always friends. Just don't let the past bring you back. Move ahead and make sure you become the parents to your kids like you would have liked for you.