This is not at all a question of being selfish. It sounds much more like self-preservation. Did you somehow fall through the cracks? There should have been several days of orientation for all new hires. You should have been assigned a mentor who is paid to help you. They should have given you the class lists and schedules when the other teachers get theirs. You should not have had to search for them.
I can begin to calculate how you can have 1,000 students a week. The lack of attention from the principal is inexcusable. I'd like to suggest several ideas.
You need to really get to know the office secretaries. They can help to be sure that you get all the supplies and things that you need. They can route you to people who can help.
You need to make an appointment and talk with the principal. Ask about what kind of support that the district should be giving new teachers, because you don't seem to have any. Has the principal been in to observe? As a new teacher, there should be several formal observations this year, with follow-up conferences. If the school doesn't supply a mentor, ask if he can help to arrange for someone to help you. Try to keep it positive, not whiny, because you don't want it to become a complaint session. You want it to be a get-me-some-help session.
Talk to others in your department. I am guessing that you must be art, music, or phys ed. Ask for how they cope with the crazy schedule. Commiserating about a situation is a kind of support.
You are not whiny and not a failure. This is more than your ever bargained for.. I know that you had dreams of how great it would be to teach, and the situation where you landed does not sound like an ideal situation. Please be strong and hang in there. Do what you can to build a support system and to get a better handle on all these classes. Next weekend, develop a long range plan for what you need to cover for each class for the remainder of the year. That will help you to feel that you have some grasp and some control.
Have your joined the teachers union? Talk to your building rep. The union may also be able to find some support for you.
It really can get better. I believe that you can make it!