Being a parent is no small task with no instruction other than experience of being parented. Parenting involves so many sacrifices and a large investment of yourself. When you see your parents do things that hurt you or taught you the benefits of hurting others; attempting to change it will require intention and purpose. It is helpful to take inventory on your needs, issues, stressors and desires. That will assist you with identifying what you want or need to do different and support your ability to change it. Identify what is working and what is not. Challenge yourself to identify the behavior your intend to replace it with and move forward. Seek therapy and support.
"There is no such thing as a perfect parent. So just be a real one." - Sue Atkins