There's a reason for everything, we just don't always understand what they are. Try to talk about it and understand the reason. If you can get a handle on why, your answer on whether to give up or not should be clear.
I haven't spoken to my best friend in months. Right now, she's going though some things that she needs to go through alone, and I'm giving her the space to do that. If she comes back, I'll welcome her with loving arms... but I can't chase her. Sometimes, people just need space...