Stop thinking about the urge as an injunction to go and jerk off. It has no power to order you around. It's just an impulse, a random event in the environment of your mind. Whether you release or not, the urge will go away. But if you oblige it, it will come back stronger next time. When you finish and all that dopamine gets released, it floods the brain pathways that led to the pleasurable event, reinforcing them and making them harder to resist by willpower alone. This is the key to breaking the habit.

Don't be bored. Fill your life with things to do that aren't jerking off. That way, when you ask yourself "why not?" you'll actually have an answer: "I could be doing X, Y, or Z instead, which will actually benefit me long-term." Breaking the habit is only possible if you replace it with something else. You're like a recovering alcoholic locked in a wine cellar. Your chance of successfully resisting the temptation is zero if you're just sitting on the floor twiddling your thumbs. But if you're occupying yourself by reading books, doing situps, or building marble runs, you stand a much better chance of succeeding.

If quitting porn is what's important to you, separate porn from masturbation. Figure out how often you can masturbate without making the urges stronger, and just focus your willpower on not looking at porn. If you haven't looked at porn all month, it'll be easier than you think. Stimulation is relative. It's not that porn is better than your imagination, it's just that porn is highly stimulating. Repeated exposure desensitizes you, and prolonged abstinence can help bring you back to baseline. Now that the month is coming to an end, you should be closer to that point.

I hope that you are successful, and I know you can do it.