iMessage and Text Messaging not working! HELP!

I have had a pretty bad problem with iMessage these past few days. It all started out when it wouldn't connect to my phone number. I have tried almost everything to get it to work as well as contacting Apple Support over 20 times but no one can seem to fix the problem. iMessage is currently trying to connect to my sisters phone number (FTW????) and won't allow me to send normal texts. Please help!!!!!