Lost weight but now I look tired and flat. What am I missing?

I dropped around 35 lbs over the past year and I don't regret it at all. But now my face looks kind of hollow and tired compared to before. My skin feels less full and I have more lines around my eyes even though I'm only 24. I drink water and use moisturizer but that doesn't seem to be enough. Has anyone else dealt with this after losing weight? Is there something I can do to bring back that healthy glow without gaining the weight back? I don't want to look gaunt. Please be honest but not mean. I just want to look like myself again but healthier.