DUDE. Holy shit. 29 is out of fucking control. Have you checked for ketones?? Letting your levels get that high is really dangerous and just asking for longterm damage to kidneys, eyes and extremities. Sorry to lecture but I've lived with this shit most of my life and am resolute in the fact I don't want to be blind, on dialysis and unable to get a boner.
I have had type 1 since I was 6 - my blood sugar was 44.2 when I was diagnosed!! They couldn't understand how I was still conscious. Anyhow, in terms of what to be careful with:
-Alcohol: Sugar raises the blood sugar (obviously). Alcohol can lower it. Alcoholic beverages contain both these things to some degree. With type 2 I would just try to avoid sugary beverages - even some beers can contain a reasonable degree of carbohydrates - stick to drier beers, mix your spirits with diet coke/diet lemonade whatever. Most importantly, keep a close eye on your levels. When I'm drinking (in a session) I'll usually check almost every hour to make sure I'm not too high (or low) and do insulin/consume sugar to adjust
-Stimulants: Stimulants, particularly methamphetamine (unfortunately my drug of choice) will tend to raise blood sugar levels. So, I would probably avoid these.
I haven't had any noticable effects from any of the other drugs I've tried (LSD, 2C-B, Ketamine, Marijuana)
Seriously, if your blood sugar is as high as you say it is you should be staying the fuck away from ALL drugs - your toxin-filtering organs are alrady under a huge amount of stress. But, that's easier said than done I suppose. Hope some of this was helpful and/or relevant to you.
By the way - "Drowning yourself in sugar until your organs give up" is an upside? That's fucking stupid. Death by ketoacidosis induced organ failure is not a pleasant way to go (from all accounts, anyway).