You are very young and I am so sorry you are going through this right now. I agree, run, don't look back, save yourself now and move forward with your plans. If you need to talk to someone, do it, it might help you get your feet firmly planted again. Don't talk to, this guy, no texts , emails, voicemails etc..... I think you have all the information you need and his sister has confirmed it all. That is a gift.
This is an awesome community, the wonderful people here get it and they care deeply. Stick around and take care of yourself. I know it is painful and I feel for you, but ending this now is divine intervention, keep moving forward.
Sending support and love Katie