I haven't showered since saturday
Are you doing okay? Why aren't you taking regular showers?
I don't have time
It's really important to maintain your hygiene. Lots of bacteria can grow out of sweat which can cause unpleasant odor or rashes.
I just don't really care.
How about thinking about it like this, warm and hot showers are extremely soothing after a hard day of work! You seem like a busy person, so it's beneficial to your mental health too to relax in the shower and get clean.