You're here, therefore you must be strong. At least you know your missed promotion wasn't lack of ability so you can be angry, but no need to turn on yourself, which is depression.
Have you tried CBT? Not a cure for everyone but can be accessed free. One site, MoodGYM, Not sure where capitals go, is an Australian site, but I used it free from UK and it was good, helped me a bit takes you through a six week course of learning and homework, aimed at younger adults but I was early 40s. Hope you can find something helpful.