Help for deliverance from adulterous thoughts

I have been struggling with lustful thoughts towards my father in law recently. My relationship feels fine and normal; but sexuality I’ve turned towards the idea of his father. I constantly try to get his attention and feel good when it happens which has made it difficult to keep myself from interacting with him often. I don’t know what to do most days and both dread and love having to go over to family dinner. If anyone ever found out, I’d immediately loose all respect from his entire family. They’re all beyond close, with all of the older generation, including father in laws, coming from Mexico 30 years ago; and all are extremely catholic. I have only recently considered converting; which has made this situation more difficult for me, and if anyone found out, would make it difficult for everyone all around. Most days I feel disgusting but some days I can’t stop the thoughts. It’s even worse when my son is at their house with my mother in law and I have time to myself