Scratching holes in my skin

I am not sure if what I have is eczema.
Since I was young, I have had uncontrollable urges to itch my legs. My calfs in particular.
I have spent countless amounts of money on high end and low end lotions, oils, body washes, and ointments to try and cure myself. Nothing has ever helped.
I have short fingernails. I will be sitting and I'll just start scratching away. I'll have no idea i'm even doing it. My boyfriend will notice I am scratching and stop me only for me to realize my fingers are either covered in blood, covered in a clear wet substance, and usually a gaping hole in my leg. This has left me with numerous scars of various sizes all over my calfs. This only happens from my knees down. I do shave, but I use sensitive skin shaving cream and an oil from Aveda that promises to be all natural and good for eczema.
I really want to know what is causing this. I have done a lot of research and have no answer as to what is going on. I would like to see a dermatologist, but am not in the financial stand point to do so right now. So any help that may be present is welcomed.
I have literally done everything to stop the itching and nothing has worked. My poor lower legs are a battlefield of scars and wounds now and I would very much like to know why. And why it only affects my lower legs.

Thank you for any and all help received.