I was downloading Destiny 2, roughly 140GB, the game was downloading for almost a week, due to my slow internet it finally reached 80%.

I had to restart the laptop to fix a bug in a different non-steam game. When doing this, I forgot to pause the steam download.

After reopening steam, the download was in the 'unscheduled' category, and when trying to resume the download, it told me i didn't have enough disc space, the reason i didn't have disc space is because the space was already being used by the download cache for the same game, but steam couldn't recognize that i guess.

I tried several different things to solve this,
First i wanted to resume the download and see if i could put the cache back in while it was downloading, to do this i needed the help of an external HDD in order to move the cache around, as i only had roughly 60Gb of free space otherwise.
This didn't work and resulted in the same not enough disc space error.

After consulting chatgpt and realizing that the metadata was probably relevant as well. I copied the manifest "appmanifest_1085660.acf", i thought this was the manifest with the 80% progress, until later testing made me realize it was infact the manifest of a brand-new installation showing 0% progress.

This was late at night so i decided to move everything from the old download cache into the HDD and start a new installation overnight so i could test with it in the morning.

Next day, the progress was at 3%, i copied all the same files to the HDD and now tried to reproduce my situation on this download. However, no matter how many times i executed steam using the task manager mid-download, or restart the laptop mid download, i couldn't get the same issue to arise.

Now i cleared the download cache, and wanted to see if it was possible to bring back this 3% progress with the files i had, and indeed it was possible,
I started a new installation, paused it, moved the 3% "appmanifest_1085660.acf" and also the 2 state files alongside the cache, and the download continued from the 3% spot.

After finding out that it was possible to do this, i knew that there had to be something wrong with the files i had from the 80% download. That's when i opened the manifest i saved and compared it to the 3% manifest and realized that the one i thought to be from the 80% download showed 0 bytes downloaded.
But i realized the manifest was irrelevant.

Some more poking and prodding with chatgpt lead me to try using a new manifest and new state files with the 80% cache. and this just causes steam to use the cache as if it had 0% downloaded, but the download does progress as normal.
I then tried this but using the 3% manifest and state files with the 80% cache, to my surprise, this actually had steam continue the download from 3%.
I then switched out the manifest and found out that regardless of whether you have a 3% manifest or 0 manifest, the state files take priority but when i use the state files from the 80% download, we get the same not enough disc space error that we began with.

So my conclusion is that the state files are most probably corrupted, consulting chatgpt, it told me the same thing and when i asked why i couldn't replicate the issue with the 3% file, it told me some BS about how only from 30-90% can this happen, idk.

But now I'm stuck with a download cache having 80% installed after 7 whole days, but no way to make use of the cache without a corresponding non-corrupt state file. What to do?? I don't wanna spend a whole other week to download what i already have.

FYI
ASUS TUF DASH F15
RTX 3060
i7
16GB RAM