There's no shame in admitting that you are not enjoying yourself. Everyone has different experiences in different circumstances.
Personally, like yourself, I love a solo day hike, it clears my head whilst keeping me occupied, and also like you I struggle in my own company once there is nothing left to do. I have camped with my boy, but never on my own.
I worked in an industrial yard for a few years, and the guy I worked with retired and was never replaced, 9 months later I was diagnosed with depression and anxiety, all because of being left in my own company with nothing to do or anyone to speak to.
As I said there is no shame admitting that something doesn't suit you, you have recognised you have an issue with your circumstances, and made efforts to rectify it. As for the next 2 days, just try and fill them as best you can. Become a tourist, and keep yourself occupied. There's a cinema in Chamonix, although it will be in French, a film will pass a few hours on an evening.
Hope you have a safe journey home.