The manager role is a really tough one to be in, and I'm sorry to hear about what you're going through at the moment. You've done really well coming this far (7+ years of fast food experience, with 5+ years of managerial experience), and that's something positive to look at about your current job, and be proud of too.
While I cannot say what is the right thing to do for you, here are some thoughts for you to consider, and hopefully it will help you with making decisions.
I feel, it would be best to have an exit plan before you quit your job. Your current job seems to provide you some security in terms of income. To quit now would mean you'd be faced with a new set of challenges. So perhaps take some time to make some plans, as well as a back up plan of your plan, for how you would face these challenges when you quit your job.
Alternatively, if you feel you aren't ready to take on the challenges of unemployment, you can consider adjusting your work place to work for you. For example, take some time to think through what is it that you hate about your current job? Is there someone at your workplace that can help you with what is it that you find uncomfortable at your workplace? If you speak to your boss about what you're unhappy about work, will they be willing to make some changes to see if they can help you out? Have you been able to take some time off for your own personal care (sometimes, we get carried away with work, that we neglect our own self-care. When we neglect our self-care, we get flooded with negativity and frustration as our body tries to tell us that something is wrong and we need a break)?
For your career goals, you mentioned that you like space travel, technology, PC Building, gaming and digital media. Perhaps you could try setting a small amount of time (can be 30 minutes, or an hour once every 2 days), to do a bit of research on your passion, and how can you line them up to nab you a career in those areas. For example, if PC Building is my passion, do I have what it takes to be a PC Builder? What sort of skills is the current industry looking for for PC Building? Do I need any further education? Are there any job opportunities or apprenticeship for PC Building?
I hope that helps. Always happy to listen to you and your thoughts.