Don't panic, the best place you can be as at the hospital because they are the ones who will check you out and if required give you the help you need!!! 
I know it's easy to say but get the diagnosis first!

I am just starting my 4th week of radiotherapy after being diagnosed with head and neck cancer in June of this year, yes it's quite a devastating thing to be told you've got cancer and suddenly life becomes very precious but I can honestly say the professionals who I've dealt with have been the most supportive and positive people I've ever dealt with, I believe I will survive this thing that's invaded my life due to their hard work, determination and positive attitude! I know it hurts and it'll change my life forever but I now know there's a life on the other side of this! 
I pray it all goes well for you tomorrow but if the diagnosis isn't what you want it doesn't mean you can't win, just means the games a little harder, keep the faith and fight it like you know you can!!!