It is not possible to determine. Risk of further damage or death are directly related to blood sugar levels, and no one can tell how long you will be able to control your blood sugar without medication. You probably know them well, but here are the risks of untreated Type 2 Diabetes: https://www.unitypoint.org/livewell/article.aspx?id=4e39b5e1-ab20-4770-8be0-29564e8d7a97
No-one can really tell you how long you've got. You have certainly been through a lot. And you have been fighting pretty hard, considering you are still here.
Your blood sugar levels, while high, are not terribly high and they won't kill you directly.
Sounds like you have given up at the moment. Is there a reason for this? Do you have social support?
Are there things you can still find pleasure in that will make you want to keep going?
Can I suggest that you look at your diet as a starting place to feel a little better; even if you've given up on meds and doctors. Low carb diet (meat and low carb veges) will help with blood sugar control. There are quite a few online support communities.
Are you living in a place where you can get outdoors, and perhaps walk a little.