My life is slightly insane at this point and I feel like I've actually over-committed myself with regards to all the overtime I'm doing, as well as keeping up with my regular classes. It's too late to go back and reduce my schedule somehow, but here are some tips that I have for dealing with this situation:
1. Recycle. You truly don't need to reinvent the wheel. Use some old lesson plans if appropriate and just modify if for the class in question.
2. Use the textbook. While I generally don't like to use textbooks and will often use my own material for class a lot of the time, if you're pressed for time, do the book-warrior thing for a couple weeks until you have some more breathing room.
3. Breaking News English is your best friend. Ready made lessons at a variety of levels, on a variety of topics.
4. Grading-without the stress. While giving helpful feedback is important, I simply have too many students (over 100) to correct every single grammar mistake on a 500 word essay. I will just circle the errors and make some general comments. If the students are actually interested and don't know their mistake, I encourage them to ask me.
5. Keep up with lesson planning/grading. Just because you're busy, don't get into the habit of doing stuff minutes before class. That just pumps up the stress. Try to have things done at least a couple of days before, even if you have to use a weekend day to do it.
6. Breathe. Exercise. Eat healthy food. Cut down on the alcohol. Sleep. Make the time that you have to spend on planning/ grading productive time.