Teens - Confessions

So I am doing my best to stay away from porn, masturbation, etc. Last sunday I fell on my knees before God and prayed for strength to overcome this evil habit and I was doing great and today I have no idea what happened... I just broke. I come from a very rough past (Parents weren't around,divorce, domestic violence, depression, the whole nine yards). I used to use porn to take my mind off of things, from age 15 I guess I just got addicted somehow. So now I just feel awful everytime I pray because I just feel like I am taking advantage of God's love. Please help me.