I agree with Lothlorien. All of us experience this at one time or another because of our difficult children. I've been feeling the effects of it lately as for the past 9 years husband and I haven't had anyone to help take care of our difficult children. husband works long hours and I basically take care of difficult children alone.
I try to squeeze in a bit of "me" time whenever I can. Lately, it just doesn't seem to be enough. Exercise helps me remain calm while dealing with the day to day H-ll my difficult children create.
I try to think about the rainbow at the end of the storm... Someday, (hopefully) my difficult children will no longer be living with me. I find myself thinking about this more and more often... WFEN