Why do I crave protein so much?

Okay, so ever since I could remember I've had this insane craving for protein-anything. It's not like a preference. I have a problematic sweet tooth and I like to eat sweets whenever I can, but it's not a craving. It's just me be being gluttonous and having no willpower. It's not as intense as my craving for protein, which is insane to be honest because I want it all the time, especially lately. I consider myself a sort-of healthy girl (not really). I don't ever exercise to be honest and I don't do much physical exertion besides walking and sitting down. I'm not physically active really. I'm also not doing so well on the sugar/sodium intake, meaning I eat way too much of it. I have diabetes in my family history and have a risk of getting it myself in the future (but do you think that stops me? pffft no). I weigh 96 pounds and I'm 5'2 with a petite body frame (I have a very fast metabolism so it's not like I'm underweight because I don't eat... I actually eat a lot... like three meals a day with snacks and sweets in between).

I've had cravings before, like fish and milk, but when I consume enough of it they go away. When it comes to protein I just really want it all the time. I want red meat (any meat really), peanut butter, potatoes, fish, eggs, just anything like that.

It might be because of my ridiculously unhealthy diet, or the fact I don't exercise, or maybe I'm vitamin deficient. I don't get it, but could anyone explain it to me?