Wow, I am so sorry you're going through this. Of course I have no way of knowing what's really going on, and nothing excuses your BF just bailing on you, but it sounds like he may have needed some time to come to terms with things on his own (hence retreating to the wilderness and not communicating). I'm not saying it's ok, but maybe he didn't know how to ask for what he needed: mental and physical space to process. I don't know what a relationship expert would say, but my instinct is to suggest you to send one last text message to say you miss his support and are confused and hurt, but that you hope this time away gives him a chance to think things through and that you want to talk things over and figure things out together when he gets back. When you do eventually have that talk, let him know what you need from him in terms of commitment and support and ask how he's feeling about it all. I really hope things work out for the best (whatever that may be), and I'm glad you have the support of your sister during this stressful time. Hugs to you!