No don't tell your kids you didn't want them FFS. You're basically saying to them "I wish you didn't exist, I would be happy if you had never been born" that's one of the worst things you can say to a child. I don't care if that's how you feel, that's not something you have the right to lay on your child. It's not "healing" anyone to tell a child "I wish you had never been born". It's selfish. Tell your therapist these feelings not the kid.