Dont know if spot on leg psoriasis or not!! HELP!!!

Hi. Well I have these big spots on both of my legs thats slowly spreading. My right leg started developing when my grandmother went into the hospital. I noticed from all my stress and depression the spot kept getting bigger than I ended up with one on my left. I had these spots since either 05 or 06. When its not scratched its thick and grey but when scratched it turns white and makes a lot of white greyish dust. It itches so bad to the point where its frustrating. I dont know if its actually psoriasis or not. Its taking over my life in a way. I find myself so uncomfortable wearing my legs out. I need help. Do anybody know what it is and how can I get rid of it? Please help!

Unfortunately, we are not medical professionals and certainly can't diagnose over the net. It's best to go to the doctor and see what they think. Good luck!