[Namari]

First you should try to see if you still like what you were doing and what burnt you out in the first place. If you still do then there are loads of video tutorials to help you out cover the gap. This will take at least a month to get back in shape. Don't bother applying before as you won't be ready and might fail one interview you could have succeeded by being more prepared. Train for interviews and ask the correct questions. You need to be prepared to the questions about those years and how quick you can get back to your feet. They will want to know if a burnout can still happen.

For system you can always try to get a certification.

Also you need to know if you're still capable of working 8 hours a day.

Good luck