Black Screen Of Death

Please help me with this problem. After I came back to school my Xbox One was working perfectly, I eventually fell asleep and woke up to my Xbox being turnt off (of course) so I turn it back on only to see a black screen yet Im able to pull up the guide to restart, shut down ,etc. I tried restarting, waiting 10 sec holding Xbox button down, unplugging and replugging and it still wont work and shows the same thing. I looked this up and its called "The Black Screen Of Death" yet the only solution I could really find is doing a factory reset which I wanted to avoid but I seem to have no choice.

Can you educate me of how a factory reset works as I've never done this before.

Does this delete all of my stuff? and i mean ALL of my stuff; Accounts, Achievements, Games, Game Progress, Apps, App Accounts, ETC.

Im mostly worried about my apps and game progress, while most apps I can redownload there is a select few that I use that were taken off the store and I wont be able to redownload. As for games Im worried the stuff and data I have will be gone like will my Minecraft worlds will be gone or something. Also I have some games on my Xbox that are not exactly mine but on the other account on my Xbox which was the person who gave it to me as a kid. Im able to play them if a have a Game Pass but haven't got that in years so Im not too worried. Please help resolve this issue, its really upsetting waking up in the middle of the night and out of nowhere your Xbox stops working and I predominantly use it daily.

:)