Am I done

If you have gotten a divorce, how did you know when you were done? I've been back and forth for about 2 years now and I just cant anymore. But we have two babies together and I dont want to hurt them. Everytime i get the courage up to leave, he ends up turning around in me and making me think that I'm the shitty person and gets so upset. I dont like it see him like that, so i stay. At this point I cant even explain why I feel the way I feel, I just want out. I'm numb and emotionless as he sits and sobs. I don't want to continue putting him through this, but am scared to just pull the trigger on divorce.