I think it is "all in your head" to a certain extent, because it's in all of OUR heads, too. When I first got sober, I thought about drinking 24/7 and my addiction tried every possible trick in the book. It's just like dieting - we don't think about that chocolate cake nearly as much as when we decide we can't have it.
I promise it will get better. You'll have longer and longer periods of not thinking about drinking, and more of those good experiences. Cravings can get really uncomfortable, but they do go away,so hang in there!:ghug3