Me again...I just read what Jeb wrote. I really identify with that, Jeb. I am wondering if perhaps it is partly an "artistic personality" type of deal? I can have this restless feeling, even when the circumstances of my life, marriage, etc. are stable (whatever the hell that means!) and it is usually at that point related to not having an artistic goal, not feeling like what I'm creating/spending time on is an accurate reflection of who I am, and/or being immersed in "custom work" that I'm being paid to do but is not really "me." Anyone else identify with this? 
Another question that occurs to me...am I the only one who gets this restless feeling in the Spring? When I think about the past, I am a little alarmed that I broke up with almost every boyfriend I had in this March-May window. Usually April! And here I am with this restless feeling right now. April. Maybe I need to have a "wait 'til summer to do anything drastic" policy for myself??? :)