So..he's buying a place to make a woman he's know for 5 months be happy? And he can't wait until he's legally free from you to do it? Is she getting kicked out of her place, maybe? Or maybe there is something about his upcoming retirement that is pushing him to think he needs to buy now? The VA requirements, etc.
And yes, please do stay with someone while he's in town..or if you think he's going to take things out of the house when you're not there, then have some big burly guy come and stay out there with you. I didn't think my H would do any of the things he's said and done. He hasn't hit me or anything, but he has said things that go against his very core and has had screaming rages over the most mundane things. These people aren't in their right frame of mind and are doing things that they normally wouldn't do. If he wants it bad enough, and sees you as the only thing standing in his way..well, you just never know what could happen. I'm not trying to scare you, but just be proactive.