Depends on what you mean by movie obsessions and how it is affecting your life. Do you mean obsessions as in you love buying DVDs and the act of buying them and hoarding them is getting your way or do you mean that you can't stop watching movies all the time and that's getting in your way? Or is it both?
Anyway, since I don't know your actual problem, I will just make a generalization that your obsession is both. In this case, get a trusted friend or family member to take away all your DVDs or somehow limit your access to them. Then have them closely monitor your spending or if you still live with your parents, tell them to not give you any more spending money. If you happen to get DVDs during this time, your friend or family member will then be responsible for giving you consequences such as throwing away one of your DVDs for good, taking away that DVD away from you like all your other DVDs, or escorting you back to the store to return it.
After this make a list of priorities that you need to do in order to busy yourself from wanting to watch DVDs. And let's say that after you finish with ten things on your list, you're allowed to watch one DVD or something like that with the supervision of your trusted friend or family member of course. This would be a way to reward yourself which is perfectly fine. Just as long as you don't indulge yourself, it's okay to take a break and occasionally watch a DVD after some hard work.
I don't know, this plan is pretty generic in my opinion so you'll have to come up with your own that is suited to your needs. Remember to compromise and come up with a plan with your trusted friend or family member and be sure to stick to it. Good luck!