I know that situation. Have you tried all your resourses? Asked all friends that you know who smoke. If you don't have any more friends that can hook you up go to
www.webehigh.com They list where to go in every larger city to find more bud, and the local police and population tolerance.
Now to make it last longer? Don't smoke as much. Try just being lightly stoned, it can be amazing under the right conditions. When I knew I need to save it, I would just take one hit and play a fun videogame for 3 hours. This works great if your a wake and baker, after the 3 hours are up, just take another hit, works great! I personally smoke only after 4:20, mainly because I save on weed mostly, and I don't get off work until 3. The important thing is to ration it out that way you will hopefully have some til you can get more...