It is certainly a symptom of depression. Different people experience different symptoms and not always in the same order. This is why depression is more complex than people realise. If you are concerned, I would go and see a doctor and start a set of therapy sessions. The earlier you start treating it, the easier it is. For most people, the depression has been there for a while before they notice the symptoms so you may have had it longer than you realise.
Yana,You have received some great advice and Darren is so right on. Please seek out the help of a physician and get a therapist to work with you.
Support groups are a place for people to give and receive both emotional and practical support as well as to exchange information. I think you would have the best of both if you continue posting here and worked one on one in therapy. Bless you.Kitt