IslamicAnswers.com: Islamic Advice

I repeatedly did zina and did tawbah, but I doubt if the tawbah was valid

I failed and the problem is NOT that I can’t repent. The problem is I feel like I’m not feeling ‘guilty enough’. The problem is I doubt myself. The problem is I’m doubting my Iman. The problem is now that I’m typing I feel like crying but I can’t.