Like Saffie suggests, maybe you need to look into whether some AD's might help. From what you describe, a general dissatisfaction with your life, despite knowing you have a good H, children and family, indicates the common disillusionment we tend to have in modern life. We all are vulnerable to these feelings from time to time, and they should pass. But if they persist then maybe seeking some help would be in order?
There are a couple of things that have helped me (suffering from my own depression) aside from the AD's, and aside from my renewed walk with Christ (which is more than enough) -- I have found that helping others helps get my focus off of my own problems (for example, I just completed helping in a project to gather canned and dry goods to restock the pantry for the local inter-faith soup kitchen). And also remembering to take care of myself ( through GALing) is key as well (although I must admit this has been scarce for me the last month or so).
