It popped off so idk what to do next<br ><br >

 

Sway bar link

 

They are number 6 and 7 on the diagram. REAR LOWER ARM for 2006 Acura TL

 

That's the front though..

but still called a sway bar end link.

 

It's called broken.

 

I had to replace both of them last month on my car after 242k miles. I heard a knocking noise & the mechanic lifted it up.
The originals are made with cheap plastic, but replacements from Autozone or Advance are all metal.
Was pretty cheap to replace.

 

Normally that would be a quick and easy fix but you have some rust on the bolts. I would try to remove the part first. If you have success then order the replacement. If you fail then take it somewhere.