I know exactly how you feel. losing my grandpa was very tough on me because he practically raised me. at that time i thought that id be a wreck forever, but he did teach me one thing. he told me that as long as i remember him, then hes not really gone. like i said i know its tough, and im not saying this will happen, but attend his funeral to pay your respects and says your farewells, then stay around family and loved ones for support. i know it wont be easy and ive been where you are, but i PROMISE it will pass!
good luck
Jason---Senior Airman in the United States Air Force
ps-dont think my screen name has anything to do with this reply to your situation, im an Undertaker fan from the WWE nothing more