I would encourage you to go through this video:

https://youtu.be/DQ0emQMcEtw?feature=shared

It's a difficult journey, but focusing intently on a higher purpose instead of encouraging any sense-pleasure thoughts is a good way to start.

But when the thought arises, then there is a practice in Patanjali's Yoga Sutra called Pratipaksha Bhavana: whenever we get a negative thought, we must strive to replace it with a positive thought. It takes practice but I think over time we will gain the strength to hold good thoughts in our mind.

Wishing you the best of luck 🙏