Sorry to hear about your experience. There's absolutely no need to buy again during your subscription no matter how many times your system crashes or even when you have to replace the whole computer!
Firstly make sure that whatever you did for recovery did not leave you with some trial installation of a security product -- if you used Restore to Factory Condition that could do that. It might be a Norton product or it might be another one but in either case it is essential to remove it and clean up with a special tool we can point you to if you tell us what it is.
But if that's not the case and you just have a clean install the simplest way is to use that computer to log onto your MyNortonAccount from when you first activated your Norton product (It is Norton 360?) and you should find a Download button there. CLick on that and it should download and install an activated copy of your product without notching up another activation.
Once it is installed run Live Update a few times with a reboot in between until it say you are fully uptodate.
If you have any problems when you do that let us know and we can help you with alternatives.
Hugh
