I accidently clicked on "mark all as read" after someone sent me a message, how do I view it?

So today I tried finding a way to search comments in Lemmy, but I couldn't find one (at least one that worked for every instance), so I decided to make my own one :) you only need to log in once and the program will automatically detect it for you after that (your credentials are stored locally). This would be really impressive if it turns out that there's a way to Search for comments inside of communities XD

https://lemmy.ml/api/v3 works for lemmy.ml, but when I try it with lemmy.world it gives bad request, any help?

I don't know what I did but I must've messed up somehow while deleting the distro, so now I only have 700 gigs of my total 1tb of disk space left, when I try to merge the other unallocated 300gigs of space back to the drive, it says "there's not enough space in the disk(s)". Anyone willing to help? here are the screenshots: