I have had that feeling sometimes of just wanting to throw in the towel. For those of us who suffer with depression with any type of regularity, feelings like this can sometimes come up out of nowhere. Or we get caught up with feelings about situations so much that it consumes us.
I have battled depression since I was very young, seeking out my own counseling when I was a teenager. Through my life I have had other periods of counseling. As a kid I lived with a father who had paranoid schizophrenia and he had other mentally ill siblings as well. Mental illness can be genetic. My sister, brother, and I all have battled depression at one time or another. My sister even had anxiety/panic attacks. She tried medications in the past and suffered bad side effects. I don't want to take meds unless it gets down to the point of where I can't function.
Depression is very tiring and you can feel a lack of ambition, even for things you used to enjoy doing. It does not mean that someone who suffers with this condition does not have dreams or goals. We would love to be able to take things light and get things done. I am surprised at some of the lack of sensitivity here with a few people who feel that they have all of their ducks in a row, and could never imagine having feelings of hopelessness and helplessness that such a sometimes debilitating illness can bring.
I say good for you. People who suffer from depression only wish to be like you with your energy and perseverance for life. If you have been fortunate enough not to suffer from depression it is common that you would not "get it", but at least have a little sensitivity for those people who have no choice in the matter. Counseling and medication can only help so much. Sometimes great success is reached with these methods, sometimes not. In any event, depression is not a choice. None of us would choose this.
Personally I am always fighting it and trying to rise above it. It is not easy to live with depression (and it certainly is not easy for the ones we live with) and some days are very bad where I can't see a positive light in sight. All I can do is take life one day at a time, and if I have a few non-productive days here and there I just try a little more the next day to stay positive and move ahead.