Hey there! ^^ I just joined this forum as well, so I'm mostly lurking at this point. I'm a senior in high school too, well, currently in the midst of becoming a senior. I won't consider myself an official senior until I walk back to school on September first. XD
And yeah, it can be hard to explore the trans side of you while living with your parents. I myself am FTM as well, it's been awkward, and downright painful, as you said, at times as well. @_@
So uh, I hope you enjoy your stay! :>