Increasing the total linked size by over twice the size of the added library is completely abnormal. I guess there must be some other source of code, such as
- C++ template instantiations that you use to call the new functions
- potentially large pieces of whatever libraries this "psapi" depends on
There are plenty of tools to list the content of an executable file: they should allow you to see which sections grow and which sections remain the same between the two versions of the program.