No shame. It happens cigs sometimes creep back in, especially in the hard times, and you have been through one of the hardest. You're still vaping though and that's good. The occasional pack is not what matters, it's that you still want to vape and stick with it more then you want to smoke. Don't beat yourself over something that not one damn one of us can say we would not have done if we were in your place. You have enough to deal with already.