How do you get motivated?

I am not usually a depressed person, but lately, I just can't get motivated to do anything that needs to be done. There's entirely too much to do at any given time, and I've been feeling like I just want to be lazy. I can't be, and it's extremely frustrating to me that I have way too many obligations. I dread going to bed, bc I know I'll have to get up in the morning, still tired, with a million things to do! I have 2 jobs (working from home), & I'm a full-time stay at home mom to 3 boys, ages 4 mo, 3, and 4 1/2, PLUS my husband & I currently separated as of 2 months ago (bc he cheated on me), so I'm doing it all alone. I hate having a messy house, I hate feeling so overwealmed, I don't get much help at all... what can I do to kick myself in the butt, give myself a positive pep talk every day, every morning?