6 APs is a lot.
It looks as if you just took too many tough AP classes at the same time. You have learned a very important lesson: Take things at an appropriate pace, and know what pace is right for you. It is possible to overload yourself.
This might be an issue for admissions at a small number of very highly ranked reach schools. However, these are the same schools where admissions is unlikely even for students with perfect GPAs.
To me this is more of a learning opportunity for you rather than a problem. You are learning that you need to pace yourself. Be aware that a few of the top universities (MIT, Caltech, Chicago come to mind) are academically very challenging. However tough it was to take 6 APs at once, be aware that there are a small handful of universities that might be even tougher.
However, there are still going to be a lot of very good universities that you can be accepted to (like, most of them).
Perhaps my main recommendation is that you look for universities that will be a good fit for you, and make sure that you apply to safeties.
Also, do not worry about this. You have just learned an important lesson a bit earlier than some other students will learn the same thing.