Awww, I understand the feeling of shame. I have done plenty of things in my life that I felt ashamed of. We can only live and learn from our mistakes and from the feeling of shame. You may feel this way because you feel you knew better given how he's treated you already. Now that you've realized this, I would cut ties with him completely. He is not worthy, and you did not deserve that kind of treatment. You're only human, and naturally, you were upset. Try to give yourself some slack. But I wouldn't continue hanging out with this man, and I would cut ties.