Why do I feel like everything is crumbling down on me.

I have to pick up one kid at 3:45 from school and I have to get mother kid to the orthodontist at 3:45 and I hve to be at the dr at 3:45 I have to be everywhere all at once. I cant handle this life anymore. I need to cook and clean and work and be sexually active. I'm just stressed. And I dont know why.. these are normal everyday issues for many people. Everybody deals with this so why cant I deal? I feel so powerless.