First, yes heating it back up will make it easier to remove, and as far as the hot end being ruined, you are probably fine, but you might need to replace your insulation strip, which you can get on amazon for cheap.
This is what I bought last time, feel free to peruse amazon and find some you like.
https://www.amazon.com/gp/product/B07D7NLX44/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Cleaning off the hotend is a bit of a process, but take your time and get it cleaned up and you should be fine

As far as what happened? I had a similar thing happen a while ago, and mine was due to a bad gcode file and my print head just stopped and was pushing filament out, so maybe re-slice your print and try again? There are other probable causes, but if you double check your nozzle is in tight, and your first layer is good after that, you should be fine.

If no one else replies to your message feel free to dive deeper into this reddit, others have had similar issues in the past and have had resolutions, so I am confident you will be back up and running in no time