Itunes blank white screen. And Software update problems

When i open my itunes it lets me view my library, but not the itunes store.
I have seen on other questions that I need to update my software. When i try doing this it says that there are updates available, so i hit install. It instantly says " restart to finish installation " so i dont actually think its installing anything. Then when i hit restart it doesn't actually restart, it just goes blue, then to the login page. ..

Any help?