Here's the problem that I see that you might not get yet. You woke up having a panic attack because nicotine had whipped your body so badly when you were using that your body felt like it needed poison to function. And you obliged? You put more poison in your body so that your body could go back to functioning on poison. See the problem? You didn't come out of the womb with dip in your lip. You probably didn't even have dip until you were at least 12 or 13. That means your body went 12 or 13 years without nicotine, and you gave in after 3 days this time?
I know you don't want to hear this so feel free to stop reading if you want to keep burying your head in the sand, but the biggest component of quitting is how badly you want it. Sure there will be tough times where leaning on another will save your ass, but day in and day out, YOU need to have the balls to do this thing. It's not easy sometimes and you were probably at the worst of it when you caved, but instead of powering through like thousands before you, you chose to give in. That's it. You gave up. You simply were too weak. Your body didn't need nicotine. You allowed it to happen. You weren't going to die that night if you didn't cave, but you didn't care because your desire to return to slavery outweighed your desire to be free from that slavery.
Also, if you didn't have any nic in your house, you woke up in the middle of the night and drove to some all nighter gas station to get this stuff and in that entire time you couldn't convince yourself that you didn't need it. I highly doubt you were still gasping for air when you went into the c store and bought the can. You had so many opportunities to not give up, but you didn't take advantage of a single one. What has changed in the last four weeks or so that you WILL quit this time, not you hope you can?