Senior grades and midyear reports

I’m taking 5 AP classes this year. My current UW GPA is 4.0. I’m quickly realizing that taking 5 APs was not the best idea, as it’s proving to be even more stressful than junior year. I’m getting worried about my grades. Although my counselor says colleges won’t even see senior grades, I know that the schools I’m applying to ask for a “midyear report.”

So, to what extent do senior year grades really matter? I’m not asking because I want to “senior slide,” but rather because I want to know if I should continue stressing out about keeping a 4.0 first semester. How much would it hurt my chances for schools (my top choice is Northwestern, applying ED) if I dropped to a high 3-point-something for the sake of being less stressed?

No worries, relax
If you would get a few B’s instead of your normal A’s it will not be a problem
Ed results come out early December
You will not get rescinded unless large slide of grades or disciplinary actions
Do the best you can and you will be fine
Do not go in with the idea of slacking off just do not get stressed