Your story spoke to me strongly enough that I made an account. You can do this. You really can do this.
The doctor down the road from me applied to medical school at about 40 and started practicing as a GP at around 50. You live in a country with a life expectancy of 80 - you're not even halfway yet. Programming is an incredibly powerful and flexible skillset. I'm a mediocre programmer and it has opened hundreds of doors to me each year. Your main roadblocks are the ones you build for yourself, in your own mind.
Remember that everyone starts out really, really crap at everything. Incompetence is our basic state. It takes a long time to improve any skill. Your missing social skills, and self-care skills, and happiness skills, and any others you feel you're lacking are just as easy to learn at 35 as they are earlier in life. It will take months, maybe years, but it's a worthwhile investment, because you still have decades ahead of you.
Small, consistent steps. If you're overweight, try to eat one healthy meal each day. Try to speak to a human every day, or every second day, even if it means pointless trips to the shops to thank the cashier. And so on, for everything you want to improve.
If you make the steps too big, you will get too uncomfortable and retreat. The trick is to make them small enough to be doable, and then to do them consistently.
Are your games still uninstalled? Cold turkey is a hell of a thing. It doesn't work for everyone, but if it works for you it could be really powerful.
Therapists can be tedious or they can be magical. If you haven't experimented with them, hunting for a good one could be well worth your time. It also gives you another person to talk to regularly.
Last, and most importantly, you have to learn how to be kind to yourself. This is the most important skill you can learn. Think about how you would respond to someone who was struggling with mental disease, who makes mistakes along the path to recovery. Hopefully you'd feel compassion and sympathy for them. Extend it to yourself! Beating yourself up about your failures - and you will fail, a lot, before you succeed - is a quick way to send yourself spiraling. Compassion is the way.
Good luck, and keep us updated! You can do this.