heeeydevon Excess memory use can be related to an overly-aggressive antivirus. So please try playing with yours disabled, temporarily of course. As long as you don't do anything else while testing, your computer should be safe, and you can reenable the AV and set exceptions (if necessary) afterwards.
Please test with both an existing save and a new one, for comparison's sake.
And just to be thorough, please confirm that it is Sims 4 itself using 45 GB RAM, not the system overall, as in, the value the Task Manager lists for Sims 4 alone rather than everything in use at the time. It sounds like you know the difference, but I want to be sure.
JourneymanMC The list of common errors doesn't have anything that relates to excessive memory use, and only a few elements of the crashing guide might be relevant here.