External SSD damaged & some files corrupted?

Hello, I recently purchased an external ssd for my MacBook, but now when I try to open some of the videos I have on it, QuickTime refuses to play them, VLC freezes midway through, or something else of the like with any other application I try. This only happens for certain files, and when I try to open them, the laptop loses functionality and the only way to stop it is to do a forced restart. I tried to move one of the files to my Desktop, and it tried for a while before giving me an error message with the error code 36, and then froze up again. I tried searching for this error code and found no similar experiences to mine. The files were fine when I moved them to the hard drive, and were functional for some time while on the hard drive, but at some point got corrupted. I can't find any way to identify or restore the damaged files, doing First Aid in Disk Utility on the drive does nothing, and I don't want to do anything that will lose the files on the drive, as I have nearly a terabyte of data on it and nowhere else to store it. My current theory is that at some point, I accidentally removed the drive without ejecting it first, and that caused the files to be corrupted, as it happens in batches of files at a time and has happened twice now. What can I do to restore or identify the corrupted files? and how can I ensure that it doesn't happen again?