You can do it! And if you feel like your having a weak moment just pray and remind yourself of your commitment to your father also. I think that's going to help a lot, sometimes you see things differently whenever they are affecting someone other than yourself. Keep yourself distracted and pick up a new hobby
Stay away from temptations like that saying, out of sight out of mind, don't be around the stuff. I kind of went through that too and I noticed that I had a lot of those "good time friends" when your trying better yourself they tend to drop like flies lol so don't be discouraged, I will be praying for you, Hellooo You've totally got this!