If you live near a large city with a bike co-op you could certainly find a suitable fork for cheap. If you're patient you could probably find a dead-stock replacement fork eventually, but the 0.833" forks on old Schwinn's aren't compatible with anything else so moving to a generic fork will be a plus in the long run.

Also, you may be able to use the current fork if you get a stem that 'clamps' at a different spot. It all depends on how mangled the steer tube of the original fork is but usually there is only one small spot where the stem wedge expands and bulges out the fork tube. Since you have a short frame and the stem was 'banged' in, this may not be the case. Still, you may want to see if the steer tube is still usable with a different stem. Also, be aware that not all crown races (fork cones) are the same size. The crown race needs to be a tight (press) fit on the fork. If it is too loose or too small to fit, a good bike shop can probably make it work but at that point you might want to just spend $15 or $20 on a completely new headset, or for less $, just use the lower bearing cup and crown race/for cone. Good luck!