I am nearing 30 and have likely been depressed since I was 15 years old. I wasn't diagnosed that young but the last lucid memory I have in life is being 14 and a human being, I feel like I lost something after that. Since then living has been getting hit by one wave after another. I get irritable with barely supressed anger, after it passes comes numbness so strong I can somehow paradoxically sense the pain from the void sucking my body in, then it's another wave of poison spreading through my body, making every movement, even if all that is moving are my thoughts, so hard and unbearable. There are bright spots in between, but they never stay long enough for it to be a reprieve. By now I have learned that no matter what happens or what I try it won't change how bad everything makes me feel for no good reason. I haven't necessarily abandoned hope that it will change one day, I have just accepted that it might not. I'm trying to live with it.

My questions are for those that have spent a long time with depression never going away: 

First of all, how do you maintain any sorts of close relationships ? I need a lot of alone time to deal with sudden dark moods, lack of energy and etc., most of my free time needs to be spent on trying to make myself function. I always fear that if I share that time with others they will see me for what a dark being I am. Even if they can accept me I can't just expose people to my weird, erratic behaviors and demand they be understanding. 

Second of all, how do you get any self-improvement done, how do you grow as a person and focus on values, morals and ethics when life becomes all about doing your best to function ?