I didn't sleep well last night, and then my son was being extra demanding of attention. I got upset with him, but realize he'd really done nothing wrong
It happens to everyone, being tired makes people so irritable. Being a mom is tough as it is.
I just felt so bad for getting upset with him.  
Just give him a big hug and let him know how much you love him, and I'm sure all will be forgiven! :)