You can't trade your happiness for theirs, that's martyrdom. I think you did the right thing by giving your opinion. Also, you need to protect your own piece of mind, unfortunately. It sounds to me like your parents are tired of each other, otherwise they would be able to make each other happy without having to have a third party around. They need to fix their own relationship rather than make you the solution to their loss of interest in each other.

I've been married for 30 years, my husband talks to his friends on email and the phone. I have a couple of friends I see occasionally. Mostly we keep each other company. We haven't lost interest in each other. We don't need a third party to keep us going. One of our kids lives in a different country (we moved away, they didn't). The other kid lives 2 miles away (they came with us). You can't live your life for someone else, it doesn't work.

Forgive them for their neediness, but don't let them make you feel guilty. Even if you have to do a daily routine like throwing a pebble into a lake or river, learn to let the guilt go...everyday. Yes they are going to die one day, perhaps even tomorrow. We are all going to die one day, even you. So get on with your life. Learn to speak to them whenever it suits you, without guilt. You've done nothing wrong.

Sending you photograph like that is extremely manipulative. I hope you know that.

Sometimes you just have to let go to move on.