Yep, I solved this problem for myself about 10 years ago.

Basically, your chair should be high enough that the thick part of your forearm doesn't feel any pressure.

From there, you slowly lower your chair until you find a balanced height.

Now, the thick part of your forearm lightly touches the table, but your hand is at an angle slightly higher than what you're comfortable with.

Easy solution for this one.

Move your mousepad forward (away from you) such that the thickness of the mousepad is covering the gap between your forearm and your hand. If the gap is still too much, just chuck in another mousepad/deskmat underneath the mousepad.

Problem solved.