What made you happier here? Isn't there a way to have similar experiences where you are now?
My family in America that I live with are very negative energy people 24.7, it really wears my morale down.
In England I have a few friends that are very positive energy and all 6-10 months I have spent with them I was always happy, walking forest every day, throwing ball with dog (which isn't allowed in the area I live in America, very stringent leash laws where I live and the only dog park is so tiny you can't throw a ball, its just like slides and toys for the dogs to climb on, etc pretty horrible overall), I am sure there are better areas in America, but I can't afford to live there even if there are.
I also prefer the climate of England, I suffer from extreme dry eye disease due to a surgery that went wrong many years ago, and winter where I live destroys me, and in England its not nearly as bad.
I miss Sainsburys, the food at Sainsburys is infinitely better than where I live and decently priced. I particularly miss the microwave pre-made Indian food dishes Sainsbury brand, I have an Aldi where I live in America, but their Indian doesn't come close to Sainsbury.
28 days vacation time starting basically right away for any job I might get in UK, and jobs in America I have to work 10-15 years before I earn that many vacation days, so I am always demoralized cause I know I don't have much to look forward to, where as in UK if I had a work visa I could go work a warehouse job, play with dog after work, and look forward to a long weekend vacation with my friends often.
It's a lot of things... these are just some of them.
I will say it is nice having my dentist in America though, I get cleaning every 6 months and have an amazing dentist... in England I am well aware I would never get a dentist... but that is only pro I have for America... soo... lol