That isn’t memory. Which is why your thread title made absolutely no sense to me. I kept trying to understand how a laptop could keep increasing the amount of RAM available to it. Also how that could be anything other than a really cool thing if it did happen.
What you’re talking about is storage space, and the fact that your laptop somehow ran out of it. Interestingly, I had the exact same thing (minus the absolute hit-the-wall part) just a couple months ago on a Mac laptop. Turned out to be a rogue antivirus program called Malware Bytes was attempting to download something (probably its own update) and was depositing 220 zillion small files in the TMP folder so my available free space was shrinking: 650 GB, 400 GB, 210 GB, 86 GB, WARNING: you have only 605 MB of free space …
It repeated itself (I nuked all the little files from TMP but they came back) until I deleted every piece of Malware Bytes.
Probably no bearing on your situation, but make use of some utility that can tell you exactly what is occupying your hard disk (even if it requires removing it from your laptop and plugging it into some other computer for analysis) and see if some rogue process is filling up your disk. If you have a Mac or access to one you can use Grand Perspective, for instance (and it can analyze an NTFS disk as easily as anything else)
And don’t call your storage space “memory”, please.