Confusing question, maybe you'll get it?

RiRi , P & PJ’s Mom 💗💖💙
If I do what I need to, I feel better, but if I continue not to do the things I have to it just builds up and makes it makes me feel worse (depressed) overtime. How do I stop dwelling on the things I have to do everyday so that I actually don't tire myself out from doing them at all? 
Sorry if confusing, it's just that I'm noticing that I will dwell on having to do something so bad to the point that I can't sleep at night, it tires me out from doing anything at all. I mentally, which it eventually turns into physically, exhaust myself. I'm trying to learn how
to get more done during the day.