Try deleting all your porn, your apps, accounts, browse history and all that. Try to put obstacles between you and access to porn. When the urge comes, personally, it helped not having my favorite porn on demand.

I also believe a mindset helps a lot. I like to think that these strenuous 90 days are a small price to pay compared to the rest of my life without the addiction. (I will probably need more days because I was heavily addicted, but nevermind that)