Finding a good trainer to help you along would be at the top of my list for sure. It's extremely hard to go out and "fix" things yourself, there's no substitute for experienced eyes on the ground.
Since you're just coming back, I would just keep things really small and simple until you feel more comfortable and your horse gets more fit. Single fences, logs, nothing too big or spooky at first. Trot lots of things and canter away, you both need to stay rhythmic and relaxed, and concentrate on getting your horse really tuned in to you. You choose the exact spot on the jump you are going over, you choose the moment your horse's feet leave the ground. Don't allow any rushing or anything. Then concentrate on having a good canter to the jump, balanced and relaxed but forward, keeping the horse in front of your leg. Don't worry about seeing the distance every single time, that happens naturally and as long as you have a good canter, it doesn't matter if the distance is a little off. When in doubt, add a stride. Waiting is never the wrong choice! Make sure you are riding quietly and positively, supporting with both hand and leg, and sitting up with shoulders back, eyes up. Working on the little things to start will seem boring at first, but you and your horse will progress much faster in the long run. Once you've got all the basics re-established, the rest will come quicker, instead of just going out and bombing around with no real intentions or goals.
Don't worry about doing a lot right off the bat either. Gradual is better, and since your horse is coming off an injury, you will have to be very careful about not pushing too fast and be extra diligent about proper conditioning as well.