When I was a kid, whatever I left laying around the house, my mom would pile up on the bottom few steps--headed upstairs. If she saw me heading in that direction, she would say, "Take your stuff up when you go!"
I cannot describe to you the sinking feeling this gave me. It was awful, the worst task ever to reach down, pick up my stuff, and carry it all the way up the stairs. Most of the time, I whined and groaned something like, "I don't waaaaaaaaaant to." (Either that or I would avoid going upstairs for hours so I didn't have to do it)
My Mom's response (with a smile), "Do it Not Wanting To!"
She adopted this phrase for many things. It was infuriating, and at the same time---liberating.
Let's just say you really really don't want to go to the gym today. But if you don't go, you're not going to meet your goal for the week of going 3 times (and you really aren't doing anything else). So you have this "should" feeling at the same time as your inner whiner is begging you not to go. When you admit you don't want to, and tell yourself to do it anyway, you've relieved your "want" from having a say in the matter. Surprisingly, the dread becomes less severe when you've acknowledged you're not crazy about what you're doing next.
Chances are, if you do those pesky things you'd like yourself to do that you don't feeeeeeeeeel like doing, you'll feel better about yourself and your productivity at the end of the day.