First take a deep breath and relax! You can’t turn back the clock, don’t worry about the past, focus on the things you can control. You can focus on your current grades, standardized tests and your essays. It’s my understanding that colleges like to see and upward progression in your grades. If you can show that, it may offset a slow start. I would also work with your guidance counselor to put together a realistic set of schools to apply. Finally try to cultivate teachers from this year who will write stellar letters of recommendation.
Finally, outside of the HYPMS of this world, it doesn’t really matter where you go. After your first job, nobody cares where you went to college. Don’t beat yourself up, it won’t change anything, your progress has shown you’ve matured.