[CLIENT], [CRASH] My game keeps crashing on PBE and normal servers.

My game is constantly crashing on PBE and normal League of legends servers. This is happening right when i finish champ select and should be put on the loading screen, if I am on PBE it just shows a blank white screen then takes me of the screen and says do you want to report this to bug splat or restart. The first few times i tried to restart then i just decided to go to bug-splat and say my issue but i did not put my email address because i thought it would be a one time thing. So just incase i decided not to play on PBE for a bit because i did not want to ruin other people's experiences, so i went onto normal league of legends servers and picked zac in champ select motivated my team we could win the ranked match even though we had an autofilled support and then i did not get into the game or even to the loading screen for some random reason, and i then restarted my computer for it would not even let me escape the blank screen ( this time black with a fading hint of green). Please help me. And thank-you for your assistance. [zombie-nunu-tears] Oh and if you can help me loose my low priority my friends wont want to play with me if i have low priority. and even if they do i dont want to waste their time. Thank-you again. [sg-soraka]