Selfies are usually harder to adjust. A good close-up with a tripod instead of the arm stretch or the mirror is better. Any camera with RAW or tiff output is a lot better than the jpeg that comes out of the smartphones. The jpg artifacts plus a small number of pixels image may hamper your ability to adjust properly. The more pixels in the area of adjustment, the better.
Before doing any area or spot mods to the image, adjust the color temperature of the photo by decreasing the blue and green sliders in Levels or use Curves. Too cold (bluish or greenish) image may hamper this mod.
Usually a lasso tool along the faceline in the 5 o'clock shadow area with a feather of 2-4 pixels for starters, you may have to come back to increase the feather range later. In Layer, new layer via copy. Then go to Hue and Saturation tool and select Blue instead of Master. Usually the shadow shows blue. Decrease the blue slider a bit and increase the lighten slider a bit. Try the hue slider to to change the blue component to an orangeish hue to match the rest of the face. Experiment with the sliders. You may have to go to the Levels if you have Photoshop Elements or use Curves in CS. If you are satisfied, merge the layers, otherwise, delete the layer and try again with the lasso tool. I haven't done that but I have experience with Photoshop plus I had a darkroom since 1968.
Joelene