Unfortunately, this is a terrible effect of having WZ Edits. There's two main factors which cause this, though.
1. Client Memory Leak. Destructor issues in the client prevent it from freeing memory when it needs to. This issue only occurs when you're utilizing WZ files, as it's actually an issue in regards to the WZ library cleanup function not being called. I guess this was something OS-dependent because it was never an issue on XP, but only became a problem after Vista was introduced.
2. Your WZ Edits. For every wz edit that you've applied to your server, you're saving tons of images (I can tell). Whenever you're saving these images, you're saving them in a format that eats up more memory because they use more space. Most of these images can be saved in other pixel formats that use less size. However, this isn't really made possible in HaRepacker, WzRepacker, HaSuite, and probably the repacker you're using. While I suggested the feature for HaRepacker-resurrected, I'm not sure if the implementation of it is all there (and working entirely as intended) or not.
My first suggestion would be to try using HaRepacker-resurrected. Although, you've already re-saved all of your images previously under a higher pixel format, so it'd probably just do the same. Assuming that this works, I would try and get all of my custom XMLs and re-paste them into clean files. This way, all of Nexon's original entities are unchanged.
As for the client memory leak, unless you're experienced enough to code-cave your way around the client, you won't have much luck there. I might release a fixed client for v83 (or even a tutorial) in the future though since it affects all pre-bb versions.