I told a BIG ... FAT...LIE!!!

My job has been very stressful lately.  I work for an automobile dealership.  I'm sure you have all heard about the hard times dealerships are having - it's all true.  Anyway,  there has been a lot of downsizing at my company.  Everyone is doing the work of four people , yada - yada - yada.  I know I shouldn't complain, I still have a well paying job with great benefits.  Still it gets tough to wear so many hats and try to meet so many expectations.   I feel that I am not working up to the best of my ability and really have no motivation - I am in a real funk.  I took a week's vacation to have my surgery.  I did not tell my boss what I was having done, just that I was having surgery.  Only one person at work knows I had surgery.  Soooo... I was supposed to go back to work tomorrow.  I feel physically well enough to return. But----Mentally - - - I am just not ready.  I can't face the stress.  I have vacation days to take so it's not like I do not have the time available to me.  Well, I called in & told my boss's voice mail (yes, I'm a chicken) that my Dr. does not want me to return to work until Monday.  I'd like to say I feel remorseful, but I don't.  I feel bad for the co-workers that have to pick up my slack but that's about it.  I really need this time for me.  Does that make sense???