Slack off, schedule

Hi,

1) "I was up to my ears in schoolwork, so I was forced to slack off on my last essay."

What word could I use instead of 'slack off'?

2)

"My schedule for tomorrow is full."

"My schedule is full tomorrow."

"My tomorrow's schedule is full."

I'd use the first two sentences but I heard some people using the third one as well. It doesn't sound good to my ear though.

What do you think?

Thank you.