1cm thick white strip covering part of my screen+more! HP laptop

Hello, I have a HP Pavilion laptop
I tried e-mailing HP about my problem yesterday as soon as it happened but I still have not heard back and I'm getting worried about my laptop.
So I was using my laptop yesterday morning and it was completely fine, a-okay, but I shut it down, put it into its bag and then headed off to work, I had it turned on again approx. 40 minutes later and now there is a approx 1 cm thick white strip down the left of my screen and I want to know why. Everything that should be where the strip works fine, it just won't show anything where the stripe is.
I restarted the computer, done a hard reset.
I saw something about pressing F10 when booting up laptop but when I attempted that it caused my laptop to beep really loudly ,like it was about to explode so I just turned it off again and since then I've just been using it as normal (with the stripe done the side).

Also occasionally my laptops screen will flash black for less then a second and then everything is okay.. its been happening more and more recently what could be causing this.
Any help would be greatly appreciated.