How do I control myself when I'm having the urge to relapse?

This is a tough one man but I have come to the realization that it's not the urge you're fighting. Sexual arousal and the desire for sex is a natural thing. What you're really fighting is your own mind. When you have an urge pause and reflect. Ask yourself 'where is this coming from? What am I actually feeling right now?' Chances are you'll say 'well I'm feeling some discomfort now because or x, y or z.' An urge is only very rarely just physical arousal. Your mind will always want to take the path of least resistance because it uses less energy that way, and that's a good thing. Imagine if you had to think about how to eat every time you ate, you'd go crazy. Your brain has now formed strong neural pathways with porn. It doesn't have to think about it. Every time something challenging, unstimulating or uncomfortable comes along your brain is vulnerable to hijacking by porn because it is just so easy to do. These patterns have become ingrained emotionally as well and in my opinion feelings always trump thought. So my advice is more than watching your thoughts watch your feelings when you have an urge and then try change those feelings. The urge will dissipate very quickly when feelings of stress are replaced by feelings of joy.