We need more information, like is the text multiline, do you need only horizontal fitting or both dimensions, etc.
Beside, similar questions have been asked in the past (not so long ago), did you made a search?

sorrt abotu that :)

That's indeed a relatively hard problem (like many problems with fonts), even harder as most fonts in Processing are bitmap, so hard to change in size (while remaining good-looking).
Well, supposing here that you want to reduce the size until it fits in the given box. Otherwise, I am not sure what you expect.

how do i get the text that got put in the text() command back?

You probably need to manage wrapping yourself, using text metrics functions.