This is an answer-by-reference, I suppose, but I've found PJ Arends Image Viewer extremely useful when debugging graphics work.
Image Viewer Utility[
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You can see what's in a bmp, or DC at each step. Very useful when playing with different "rop"s and so on.
For all we know from your code, the initial LoadBitmap doesn't even work, so it's best if you debug line by line using the debugging tool I linked for you.
Good luck,
Iain.