If you get hurt because your body goes into conniption fits as you start to flare your canopy, don't wimp out and try to blame your doctor or the DZ owner or anyone else. I want to resume jumping after taking a break. I started jumping two years ago and ran out of money and time after about six jumps. Whether you have to start from square one depends on several factors. Sticking with the same training method and same DZ increases the likelihood you'll be able to receive credit for at least a few of your six jumps.
Many students take breaks in their training and most DZs have sensible retraining policies.
The best thing to do is take your logbook to a nearby DZ and discuss the matter with an instructor. He or she will help you determine the best way to proceed. You'll certainly receive extensive refresher training on the ground before going aloft. We don't know of any sources of such training. One reason it's not more popular is the lack of suitable equipment.