Just destroy the DAT (score dependent on what you're looking for but a 21+ AA/TS is pretty nice), get your shadowing and EC hours, write a touching but not schmaltzy PS, line up your LORs based on the schools you are applying to, make sure those get in on time, submit in early June, check out the SDN interview feedback prior to your interviews, get enough sleep as consistently as possible, and everything will sort itself out.
Personally, I had one F, a D+, a D, some Cs and a semester of Ws from a year in which I had rather unfortunate circumstances. A few Cs won't kill you. I even had a 15 on the PAT, my LORs all came in late July/mid August even though I'd asked a few times starting from the December prior to the June I was applying, I even applied to a few more schools in December. I heard back in 2 weeks from those schools even though my application was so late.
There are so many little, weenie mistakes you can make that can add up, setbacks beyond your control, or even major deleterious life events that make you think you've ruined everything. Generally speaking, I think you can often make up for them with something else. I know some of the dental schools practice holistic admissions and some like a reinvention or redemption narrative. In the grand scheme of things, 2 or 3 Cs won't destroy your application. Chill out, get your 7-9 hours of sleep, and treat yo self once in a while.
