Wife cheating with a mutual friend

I feel like I have encouraged my wife to have an affair with a mutual friend. My sex drive dried up some years ago and from that we as a couple became less intimate. my wife has always been way more sexual than I am. Before we met she had 'lovers' and was not interested in a relationship. We have been married for 15 years and we are now retired and living a new life in a new town. She joined a reading group and met this lovely man. I am not into reading like she is and so it was great for her to have someone to talk to. This I encouraged. I was busy renovating our old house. About two months ago she became different in that she was less talkative and more distant! I snore a lot and that has always irritated her but now so much so I sleep in our spare bedroom.
She stopped inviting him around for a drink or a meal and now visits him. I said could I join them one night and she said what for? I said for company and she said they talk books and teaching (both retired teachers) which would be of no interest to me.
Last Saturday she was going to meet him as usual but I followed her. They met in the park and just from her body language I could tell she was like a teenager running towards him. They kissed and hugged then walked off hand in hand!
Since then I have busied myself and almost ignored her! I overheard her on the phone saying I am impossible and it is painful! I can only presume she was talking to him.
My fear is I have no money apart from a tiny pension! She owns the house and we are both in a new town with no jobs! He is married late 60s to a woman who he cares for as she has demntia and he won't leave her!

I don't know what to do