It could just be that weed is not for you. If you try again roll a small joint and take two tokes from it then put it out wait 15 minutes then see if you are stoned enough and repeat if neccesary. A lot of people get paranoid and panicy when they first start smoking. I had some mad paranoia when I started smoking. Even though I have been smoking for years I still go easy on a new batch of weed till I have gauged how strong it is. Getting stoned beyond your comfort zone isn't fun.