TOAD seems to use an enormous number of GDI Objects, it's always top in Task Manager, if I show GDI Objects column in "Details" tab.
Any reason why it's often thousands? Even if I only have a single connection with a blank editor?
GDI leak or perhaps the way you handle glyphs is incorrect? (Perhaps this GDI monitor might help : https://www.nirsoft.net/utils/gdi_handles.html )