Nothing you can really do besides reloading.

And in the future, save more often, and especially leave your autosaves on.

So frustrating, how they keep releasing this game with a major flaw?

I have this same problem. I just reloaded and have avoided the Dawnguard quest line ever since. I know it’s not a solution, but I’m not sure there is one.

So I put in a good 10 hours in this game and once I escorted a vampire chick to her dad he turns in to a monsters and just stares at me. Nothing I can do, iv tried everything and cannot get out. My last save is 3 hours before that and was wondering if anyone knew a way around it.

Vampire bug