Language / "to be" (e.g. 'be yourself') [23]

wow, way off.

this is confusing because words like pisać are: –szę -szesz, and since "be" is być it seems to translate differently. any idea why?

here is the full sentance I'm trying to translate. I'm doing random stuff to learn better.

Przede wszystkim bądź wiernym sobą, jeśli nie da się w to swoje serce, odejć
Above all, be true to yourself, and if you cannot put your heart in it, take yourself out of it.

if you have any critique this would be great.