2 year old.

Are there days when you can't wait till your chikd(toddler) takes a nap? I have a stressful job and now my son has a cold on top of everything... Today he fell and would not stop crying and said he wanted to take a nap. I was saying in my head "thank god". Is this terrible of me? I'm sitting here thinking I'm a terrible mom. I work 3-3am, so running on little sleep, HATE my job, have a 2 year old who is in full blown terrible two stage, and is sick.