Mike, resize it is not difficult at all. Set the resolution to 200. Set the width or the height to 600 pixels. The limit must be 600. Save the image in JPEG, with the quality option on 8 and check the Baseline Optimized box. That is all.
Regarding the image, I think it lost details for sure. I can see that the Dof is good and also that you have a good composition. I hope I was useful. Regards, Marília
Nice macro; I think it would look better by playing a little with the levels to raise contrast and also a crop, to remove the blank space on the left side (see suggestion). regards