while I agree that your reach is a bit too much, I would take note of foot position too. The more "center" I had the pedals, the quicker the discomfort set in. Moving to have the pedal be more towards the frontish-center, right before the arch ended, gave me positive results right out of the gate & for those longer rides.
Note* For some reason, the change in foot placement effectiveness was applicable to the road bicycle. I didn't feel much if any positives for the MTB.