Christian man having problems?

I'm a 14 year old black boy, and I gave my life to Jesus when I was baptized in June a week before my birthday. But there is one big problem. I was a addicted to , and I am still struggling and praying to break out of this. I haven't watched it in a week, and I feel good about it, but this always happens, where I can resist the temptation for a week, but I fall for it again the next week. I always pray to God to help me with this, and I know he is working with me to breakthrough this. I feel like I was taken over by the devil, and that I'm a bad person because I kept doing it over again, and I knew it was a bad thing because it is ual immorality. Do I need to get baptized again, because I don't know if I have lost the Holy Ghost, and my salvation, because of this, or is repentance enough?