What can I do with a disgustingly sweet red wine?

Serve is as a Desert Wine.

If you want it as wine, add a bit of strong tea and balance it with a bit of lemon juice. Or make sangria.

As a bolognese sauce usually improves for having some sugar added, maybe that?

I have you covered - throw a few cinnamon sticks and a squirt of lemon in and use it to poach pears.

Not my picture (I wish it was)!

Donate it to someone. 

Make https://www.rabbitandwolves.com/vegan-coq-au-vin/

I know, I know, your vegan but the recipe I offer from that site is vegan. 

You can make many different frostings with that overly sweet wine. Let's see https://www.onegreenplanet.org/vegan-food/15-sweet... There's one. And there are 9 other possibilities there as well although some of those ask for a savory wine. 

https://www.supercook.com/ is a site that allows you to input all your ingredients on hand and it'll offer you recipes based only on those. It will, after that offer more recipe suggestions that may need additional ingredients. Yes, you can tell it to only offer vegan recipes and/or only dinner entrees or just breads. It offers a LOT more filters. If you do sign up, use of the site is always free and it will remember your ingredient list. Just go there once and it'll forget. 

https://www.connoisseurusveg.com/red-wine-cranberr...

Use it to deglaze a pan when cooking or when a recipe calls for you to add wine (i.e. beef bourginon).

Reduce it and use it to top ice cream. 

Make beef bourguignon with it.