Your bow hand drop is (I think) a result of having the center of pressure of the bow grip too high in your hand. That and your (again IMO) to low of a string elbow is upsetting the draw force line and causes the bow movement and hand drop.
The draw force line is a line that goes from the center of pressure of the bow in the hand to the arrow nock. Then IF you extend the line back to the area of the string arm elbow, that will give you a good position for the elbow.
Said another way, if you draw a line from the center of pressure in the bow hand to the string arm elbow, the line shout go through or very near the arrow nock.
Arne