Just a personal word of advice - always keep your work separate from your personal life. Meaning keep your bosses, your coworkers at a safe and professional distance, it really does make life much simpler and less complicated. Don't risk your professional relationships by making them personal. This is also why workplace romances are discouraged, but it goes for friendships too. Yes its always great to be nice to people, but keep it at a surface level for the sake of your mental health - at least that's what I need to do. I can't mix my work life with my personal/home life as far as relationships go, it's just too much.
You can either find a job you really love doing (or at least don't mind doing) or you can make this job work for you by shifting your perspective on it or by finding ways to lower your work load. Jobs should not be causing a person so much stress that it brings their entire quality of life down. No paycheck is worth that sacrifice.
If at all possible, do not take your workload home with you, leave whatever you're doing at the office and only work during business hours.
As you get older your b*llsh*t meter will cause you to stop allowing users or critical people into your life. You can either set up your boundaries now, or later, but eventually they will come up anyway. There is huge power in no thank you.
Look ahead, will you regret quitting this job in two months? six months? Are you just going through a hard spell right now but after this workload it'll ease up and get easier, or is this a constant thing?
By the way, being lonely can be a blessing because it allows you to totally focus on yourself and take steps to improve your life tremendously. Millions of people feel the exact same way you do. You aren't alone. Your family is always a phone call away, not a plane ride away.
"There just aren't that many left and if I'm honest, a few of the ones left aren't that great either..." They weren't there to begin with - you only thought they were, so technically they were long gone before you even realized it. Congrats on cutting those ties.
Don't move somewhere just to find one decent friend, you need to make friends where you are, not chase people around the globe. You can never get away from yourself - and that's your best friend right there.
I would advise you not to relocate at a time when you are already very stressed, unless you're talking about moving back in with your parents or someone who is very supportive. I would look for jobs in your current area, and with the knowledge that you're going to quit your current job anyway that alone should ease the stress of the workload, but if you have to leave, then do whatever feels right.