For me, sometimes I need to have a pity party. What I found helpful is to put a time limit on it. For example, I would tell myself, my pity party can last all day, if I was particularly down. Or I might just need a shorter pity party. Putting the timeline on it kept me from going really far down and not being able to get back out.
When I allowed myself the opportunity to feel those pity feelings, instead of trying to ignore them, it definately helped.
"Rest if you must, but never quit". Anonymous.