It was more or less clear from context that you were aiming for "habitually" and "incredulity", but a reader should not be made to guess the proper meaning of words just because you guessed at the proper spelling.
I've been guilty of such gaffes myself. I once thanked a family who'd hosted me during a language-learning vacation for their "hostility" instead of "hospitality" *facepalm*. However, in my defense, I can at least claim that I'm ESL and was a long way from being fluent at the time ... on top of being a teenager too lazy to fetch the dictionary despite having a gut feeling of being off somehow. *wry grin* (And yes, I apologized later.)
You, though, mention in your profile that you've been writing fanfic since at least 2002, which puts your age at around 30 years (if not more; IIRC, the alt.creative Usenet groups were for adults). You should know that guessing isn't good enough.
Edited to fix an html tag
If you had actually looked up what you wanted to say, surely you'd have noticed that the words "habitably" and "incredularity" (to give just two examples) do not exist.