Frodo,
I'm going thru some depression in my life right now. Yesterday all I did all morning was cry. Later in the day I forced myself to work out. I didn't go anywhere; worked out in my apartment. I felt great afterward. My self esteem was back, I wasn't tired any more. I know that the one workout didn't make me thinner, but I had hope that if I can keep on doing it, I will start looking and feeling better. I just felt much better about myself knowing that I'm taking steps to take care of myself.
I hope this helps. Good luck to you.