Its difficult to live with this sort of thing. Depression, is indeed a life sucker. I have dealt with it since I was old enough to even know what the word meant (probably around 6 or 7). I have gone through several medications, and sat back and watched myself change from a semi-happy person and into a unenthusiastic irritable pool of darkness. That sounds quite dramatic, but really. I think the first step to getting better is to identify everything that is wrong, within yourself. Its a hard thing to do. Uncovering dark holes can sometimes be draining, and make you even more upset. It is important to keep an open mind, and examine yourself from a distance. Discover what makes you tick, why you are losing those qualities you love, and how you can get back your exuberant wonderful self. It took me a long time to finally quit taking medication. I personally dont recommend it, its a bunch of shit that makes life worse. Try exercise. Walk outside for long amounts of time, run, play DDR, lift weights, do something physical. Plant flowers, find an animal to adopt. Invest your time in caring for things that cannot care for themselves and you will gain a whole new world of insight about yourself. If you dont have the motivation or desire to do that, MAKE yourself do it. Because finding answers and happiness is about forcing yourself to do things. Maybe I am just babbling and wasting my time, but these are things that have helped me, and continue to help me improve. 

I have been suffering from depression for years.  I've dealt with it mostly through writing, but lately that has not been enough to pull me out of it, so now I am seeing a counselor.  I highly recommend therapy.  There are some places that will offer therapy for free or at a reduced rate based on your income.  So, money is not an issue when it comes to getting the help you need.  I hope everything works out for you.

Sounds like you're used to being the giver, the supporter, the helping hand, the shoulder to cry on. It's okay to not always be generous and sweet and available to others. It doesn't make you selfish, you are going through a lot at this time. I think what you need is a good friend to sit down with you and listen, and give back to you the attention you have long provided everyone else. Everyone has periods when they feel low, but if it's fairly severe or going on more than a month or two, maybe you ought to look into professional help to get you through things. Nothing to feel guilty over, if this is the lowest it's only getting better from here. It seems like you hold yourself to pretty high standards, so be a little forgiving of yourself. What makes you happy? Is there anything new you want to try? Allow yourself time to go through the motions. Before you know it, oncemore are going to be fabulous.