I've always had dark circles and eyebags since I can remember but I don't think it's caused by stress or staying up too late or not being able to have enough rest. I do remember my mom saying it's hereditary since I saw some of my aunts also have prominent eyebags o_O Eye creams also don't work...
A second opinion never hurts, especially if you feel that there's something that your current doctor might be missing. I can refer you to my gynae if you like. His name is Dr Christopher Ng at GynaeMD Women's & Rejuvenation Clinic.