Christie, I think you have misconstrued the audiences intentions here. The phrase "you suck" is actually intended to show appreciation for your efforts. It means that you, like their grandmothers, do not need to be taught how to suck eggs, as you already have demonstrated your ability to suck, as it were. I can guess from the way in which you were treated with tar that you might have had a little difficulty, probably nerves and nothing to worry about in future performances, with your breathing and so some kind member of the audience applied tar to help clear your lungs. I would also hazard the guess that your first song was a rousing one as they emptied their pillows over you signifying that they felt no need of them when you were there performing. Clearly they attached the guitar to you so they could pick you out in the audience, or wherever, in the future to get you to perform again. I would not suggest that, although some of these things have been done separately in various clubs around the planet, this was normal procedure at a folk club: your performance must have moved them deeply. Please don't quit singing in public but instead learn some form of self defense, such as the Hamster Dance, so you can fend off the more enthusiastic members of your audience.