Strawberrycola I understand you and although I have not done what you are doing I have, many decades ago, done something similar. You are not a bad person, the fact you have posted means you are a good person trying to fight this.
This is what I would recommend. Buy a nice notebook which you like, private, just for you.
For seven days before you sleep try really hard to write three things which bring you joy. By bring you joy I mean think back to a Saturday or a holiday where you got to the end of the day and thought "wow that was so so good" (especially if it was something which did not cost much and especially if it was an experience not something you bought for yourself although buying things can also count).
After seven days re-read your lists. Work out what brings you joy. If it was me, it would be experiences which involve touch. That can be investing all my money in a weekly/fortnight massage at a local beauty salon. It can also be as simple as cuddling/hugging my children. Or just something like going to the cinema on my own and having my favourite treat. Or doing a hike with a local group or joining a local film club etc. Or literally meeting up with a friend for a coffee at a coffee shop which I would otherwise say was too expensive.
None of these things is going to "replace" what you get from sex, in particular sex with a very much older man. There is some deep work you need to do about why you are attracted to him. Something like this (there are others this is just a suggestion) might be useful (attachment styles people who take you for granted)
Then deliberately fill up your diary with appointments to purposefully do these things. I am not saying you will not miss sex with him. You will definitely miss sex with him. But the first time he contacts you and says "come over" and you say "sorry I cannot, I have an appointment" (for a massage or whatever you have put in your diary) the responding that way will really help you re align. This is not playing games, this is healing your soul. Good luck xxxx