Totally know where you are coming from, I have been feeling the same for sometime now - to the point where I actually got worried enough to talk to my wife about it.
I thought back to when I was feeling good about life, and the present to try and find out what is different. Had a look at everything that I have got and realised that I have pretty much achieved everything I set out to achieve, with the exception of one or two things.
So at this point, I am getting up, going to work, going home, going to bed, getting up, going to work, going home, going to bed, getting up, going to work, going home, going to bed, etc etc with no direction.
I dont have much to complain about at all - have a good business, great family and friends, but still find myself down in the dumps...
So what I am hoping will fix me is I am currently laying out a whole new set of goals for the next few years to give myself a point in getting up in the morning... to be honest, even this is hard because I am pretty down and need to be in the right frame of mind to do it, but this may help you?
I really enjoy your contribution to signs101 Mosh, and know what you are going through!!