How can I build a fulfilling, less stressful business/career?

First, having your basics covered is huge. You can optimize how you use that money by improving your cooking skills and making healthy, delicious meals at home. This will be a major boost as you work on everything else. You'll not only save money and get healthier: you'll have something luxurious to look forward to with every meal, once you have the skills.

Two, if you have some basic coding skills, you should be able to find freelance work online through Upwork or whatever. The pay isn't great, but it will help you to grow your skills, learn how to work with clients, and maybe most importantly, build your confidence. You might not believe you can be a professional programmer right now, but you will after getting paid for several jobs where the client came away satisfied.

Third, always take care of your mental health and make it a priority. Particularly if you're getting stressed out about work and have imposter syndrome when working your first few client jobs. Remember that your health is non-negotiable. Do the work as well as you can, don't beat yourself up about struggling, and don't let fears take root too deeply. If you do your best, most clients will be happy. The ones that aren't happy probably wouldn't be happy with anyone.

Good luck. You can do this. Take care of yourself.

Trying to build a decent life starting in your late 30s is mostly about developing discipline. You're not out of time yet, but you will be soon, for things like developing healthy habits and some kind of plan for retirement so you're not waking up one day at 70, struggling to get out of a chair, and wondering what the hell happened to all that time you thought you had.

So before you try to take on the big stuff, you fix the small stuff: you start eating better, you start going to bed a little earlier, you start getting a little exercise. These are really important. In your 20s, you can still get away with ignoring these; in your late 30s, these become the foundation that's necessary if you're going to improve anything else.

Because you're going to need to feed your self-discipline, and rest, nutrition, and exercise help.

You have to start taking a solid look at yourself and identifying whatever self-destructive habits you've got. I have a few, as most folks do. Maybe it's spending a bit too much time on TV or video games, or maybe it's picking fights with people or being too proud to accept help or not sticking with a job for more than a few months. Whatever it is, take a good look at it and start figuring out how to fix it.

Start putting more energy into your job. If you don't have one now, then your job is to find a job. Set a concrete goal, like sending out 10 applications a day, and do that as though it was your full time job. Start networking: a lot of people get hired by knowing somebody who knows somebody. Improve your skills. Or consider finishing your education, if financial aid is available.

Speaking of finances, get hooked in to some kind of financial planning system. I use Mint. I also got my first IRA a while back and they had this really nice graph which showed me just how dire my $0 retirement was going to be. That put a lot of pressure on me to make better financial decisions, including staying put in a job and pushing for (justifiable) wage increases.

Once you have a job, you have to do the job, and then you have to come home and look for a better job. These days, there's no reward for employee loyalty. The best way to get a raise is to get a new job. You should start seeing each job as an opportunity to build your CV so that you'll look more attractive for a better job.

Don't look too far into the future and try not to focus too much on your current situation. Getting a grip on your own psychology is pretty important. That means finding ways to remain positive about your future and not feel overwhelmed by what lies ahead, because if you start feeling hopeless, you won't have the energy to fix the things that need fixing. So focus on the small stuff: simple, achievable goals, gradual improvements, the things that need to be done today or tomorrow or maybe the next day. Don't compare yourself to other people or spend time on wishes or regrets. Keep a list of accomplishments -- even the little stuff -- and add to it every day, and if you start feeling beat up, come back to that list.

37 is not too late to build a career as a developer, if that's what you want to do. But, that means developing a marketable skill set right now, and seeking out the right person that'll be willing to hire you. They aren't going to just appear right away, it's going to take time, so you have to put actual effort in to it -- every day.