How dom i remove shelves that were put up with wood glue without taking half the wall with it?

If wood glue is adhered to a painted surface, and the paint is adhered to sheetrock ... you are not facing good news.

I painted and did sheetrock for years.
Here's how I'd handle the problem.

Use sharp utility knife and cut through the sheetrock paper around object that is glued.
Once the paper is cut, you can tear off glued item and it will remove as little of the wall as possible.

Next, but some sheetrock mud.
But not your usual type.
Get the powered bag that you mix with water.
They make 15 minute set up, and 45 minute, etc.
Don't buy paper drywall tape for this job.
Buy the fiberglass tape that looks like a screen.
Clean up you wall so it's smooth.
Use knife to cut a taper edge around each broken area of sheetrok >>> this will keep the edges down so they're not sticking up
Mix up the drywall mud so its like toothpaste.
Apply mud into wall damage.
Here's the trick ... do not build it up so you have to sand it off.
Keep it low.
Put the mud on the wall.
Push the tape into the mud.
It won't be perfect.
Smooth as much as possible using your 6" drywall knife.
Do the project in stages.
Let it dry.
Take your 6" mud knife and use it like a spatula to scrape down the high points.
Keep it low so you're not sanding.
Mix more mud.
Apply a THIN coat over repair.
Let it dry.
Scrape it again with the mud knife.

Bring a table lamp over to where you're working.
Put the table lamp up close to the wall so the light casts across the repair.
The light will let you see the high and low points in the repair
Keep floating mud in very THIN coats until the wall is smooth
Put a coat of paint over repair.
Use the light again to look for dips and weaves in the surface.
Smooth it out with the mud
Paint the wall.

If you get stuck in the project, answer back and I'll give words of encouragement.