I've been feeling the same way and have been battling depression for years and years (comes...I fix it and then a few years it comes again). I know it's the worse feeling in the world feeling like that and everyone around you says "cheer up". Trust me...if it were that easy I would. I know you feel like you are sinking in a black hole but you have to push yourself to call the doctor and get Meds/change of Meds. Something wi work for you...there are so many Meds on the market. I know you feel like the dark feeling won't go away but I promise it will. It's hard to believe it when nothing is actually causing you to be sad...you just are. But trust me...I've been through this depression so many times I know for sure you will get better. Once you see someone you will slowly start to see the sun shine and the light at the end of the tunnel even though right now you feel like they don't exist. Get the help you need...call a doctor