Disclaimer: I am not a licensed therapist or professional in any way. Just a random person offering an opinion.
I think you need to really weigh the options and give it serious thought. If you're so miserable that working made you cry, and you don't like the city you're living in, I think you need to strongly consider putting your needs first. If you're miserable, I can guarantee you that the people that really care about you will also be miserable... so you're doing them a disservice by continuing to be miserable.
It seems like you already know what to do. You really liked your hometown. You don't like London. Just go home and see how it goes. If it doesn't work out, you can restart. If it does, then great. Life is so short, don't spend it being miserable.
I think you need to really weigh the options and give it serious thought. If you're so miserable that working made you cry, and you don't like the city you're living in, I think you need to strongly consider putting your needs first. If you're miserable, I can guarantee you that the people that really care about you will also be miserable... so you're doing them a disservice by continuing to be miserable.
It seems like you already know what to do. You really liked your hometown. You don't like London. Just go home and see how it goes. If it doesn't work out, you can restart. If it does, then great. Life is so short, don't spend it being miserable.