How do i do it ? Break up /kids

So i broke up with my ex tonight i found alot of stuff on his phone talking to girls. Etc i put up with this soooo many years for 3 years him texting girls tryin to meet up with them.. etc… we have 2 kids together so idk how we are going to do it.. I really dont want him to see his kids because hes not even present . Doesnt deserve them . He hurt me snd his kids.. this family this relationship . I deserve better.. im just scared that they will do something to me and kidnap my kids or take me to court .. im done i dont want to see his face ever again he disgusts me im so hurt still dealing with postpartum my daughter is 6 months old and my son is 2 years old