Egh, jeeeeze, sorry to hear that such a thing happened to you, that sounds like it was a nasty bad experience, and to be honest, I think I would be pretty crushed myself if I had to go through such a thing.

The only thing I can really advise is to try and put that behind you; I mean, I know that's a tall order, because how do you put something like THAT behind you? But think about it, the people who bash art like that are the one's who know the least about art, and no real and/or professional artist of any media would go to such lengths to beat down on art like that. So in all honesty, it's those punks that think they know EVERYTHING, which in reality, they know nothing about art. It's dangerous to take their words personally, because they don't know anything and their is nothing to gain from their "critisisms." It's one of those instances where you have to differentiate those who criticize, and those who critique. Those who criticize art like this instance of yours just go out of their way to insult, and have no real art knowledge; where as, those who critique have better knowledge of what they are speaking, and (usually) they aren't trying to hurt feelings, just being honest and insightful. So yeah, it's hard to say how you should exactly deal with such a problem, everyone has different ways of dealing with issues, but if you were to ask me, you should try your hardest to try and put those people behind you, they aren't worth the emotional investment.

And no, your not overreacting; when people bash on personal work like that, art or not, it's very justified to feel offended and hurt. I mean, that is YOUR WORK that you care about that they are insulting, if you didn't care about your work, you wouldn't feel hurt.

As for the sketch thing, it might be an art block? I'm in the same situation, I know I have projects that I need to work on, but I only have little motivation to work on those bigger projects, and I have been doing a lot of doodling myself. Could be an art block, could be a lack of motivation, could be laziness. Either way though, it's pretty normal, I mean, it's pretty freakin' hard to be a dedicated artists ALLLLL the time, your gonna have dull moments here and there. I say, let it flow and enjoy some of the down time and laziness, get it out so then you can get it out of your system. You can work it out and you'll feel motivated to do bigger projects when the time is right.

Again, sorry to hear you had such a terrible time at the art fest. :[.

Holy shit no, you're not over-reacting even a little bit. This is absolutely the appropriate reaction.

These weren't fair criticisms, they were insults, very personal ones. It's hard to not think about these things for a long time, but I usually think like this: if these people are being this god damn mean-spirited to someone's art, they're shitty people whose opinions don't matter. I don't mean that in a "don't listen to negative opinions" way, because you are going to find better people who will much more graciously tell you your weak points, and actually encourage you to improve instead of LITERALLY RIPPING YOUR BUSINESS CARD IN HALF.

Honestly, chances are that couple are two dickheads who go around in art-related gatherings looking for people to belittle because they think it's fun.

It's difficult, but try to think more about the people who were cool towards you rather than people who were being actively malicious.