<human>: Can you condense the text into a few key points?

A little information about me: I live in the middle of nowhere with <50kB/s bandwidth at best (they have recently brought fibre to my village but my house is too old to switch and BT don't give two shits about it so our internet speed has dropped from ~200kB/s to 50kB/s due to the removal of most of the copper to be replaced with opticals).

I got in from school to find a parcel with a new battery and power cable for my laptop which has been out of whack for over two years. In these two years, I had ripped out the HDD from my laptop and installed it in my PC in order to have some extra storage space.

I planned to repair my laptop and replace the HDD alongside a copy of Ubuntu so that I could use it around the house with a small number of programmes on it, including steam but no games installed (the idea was that I would stream my games to my laptop via LAN from my PC).

So, to start with, I copied the contents of my music hard drive to my main hard drive on my PC and continued to format this hard drive ready to accept a new OS once in situ in my laptop.

Everything went smoothly, it took me about an hour to get Ubuntu up and running (I had downloaded the iso earlier this month when I ordered the new parts).

I had some trouble installing steam on my laptop but managed after acquiring the relevant dependencies to get it working.

So there I was, all done: hard drive backed up then replaced into my laptop, steam set up and ready to stream. All my games were on my steam library HDD, everything was fine.

Or so I thought.

As it turns out, my laptop's HDD was the place I had chosen to store my steam library, as opposed to my music. For most people, this would not be a problem, but due to my paleolithic internet speeds, this ~100GB collection of games (including a hefty amount of mods for Skyrim and KSP, all carefully curated to be 100% compatible and smooth as fuck) represented several solid months of downloading and many many of hours of subtle game tweaks, not to mention save-games.
<bot>: I have the shittiest internet in history and accidentally formatted my steam library's hard drive to install a new OS on my laptop.