Pounding on the threaded stud itself is bad news since that can deform the stud (fatten it) and make it fit even tighter.
The usual way for separating that particular joint is with a 'pickle fork' that is driven in between the two parts with a hammer.
If you can't get to an auto parts store to buy a pickle fork, remove the entire antiswaybar and place it into a vise so just a few inches of the end of the antiswaybar protudes out. Then take a small smooth face sledgehammer and give it some very hard whacks on the SIDE of the antiswaybar next to where the stud passes through which will pop the stud free.
Do not keep pounding on the threaded stud itself, that's not going to get you anywhere.