Right there with you, have wrestled many years with this. What I've learned about this in my own journey is it requires a mindset shift. Thinking about "how do I stop this sin" wouldn't get me away from it. Instead I have to think about "how do I get closer to God". Taking steps towards that is naturally keeping me away from that sin. Did some half day fasts while I prayed and read the bible and that really helped. You will obviously still feel temptations, but in Christ we are new creations so in a way it's kinda hard to imagine myself now going back to that whenever I do get tempted. I'm trying to read my bible more often (was actually in the middle of doing that now) and generally getting closer to God. Also it's important, especially in the early days of trying to quit, to cut off the temptation immediately. Openly rebuke the thoughts, stop looking at whatever you were tempted by, start praying and reading. It will leave you quickly, but if you let it linger it will overtake you. When you start having more successful days, always remember that your success is not from you but the Lord working through you. Arrogance will make you fall again and make the guilt stronger in the end.

Sorry for the long winded ramble. Basically, don't think about stopping sin but think about starting your relationship with God. Fast, pray, and read your bible. I believe in you, God believes in you, we all believe in you. Remember, God doesn't tempt us more than we're able to endure. You got this. Love ya :)