Why wont my phone shut off.. or better yet turn back on?

[jbec]

My s6 started doing crazy things.. switching screens back and forth.. I powered down and plugged it in to charge.. all of a sudden a blue screen popped up (wont shut off) and there is a white box with a downward pointing arrow that says DOWNLOADING DO NOT TURN OFF TARGET. In the upper left corner in red it says FACTORY MODE and some other small writing, then in blue it says SECURE DOWNLOAD:ENABLED. Am i in trouble?