Well, I'm probably too late but there's really nothing you could have done that I know about.
Your chocolate has seized up by coming into contact with water and you have no other choice but to start from the beginning with fresh chocolate. The seized chocolate can be saved and used in any recipe that calls for chocolate melted in a liquid such as cream or milk. Sorry
Don't throw out the seized chocolate. KE is right, incidental moisture contact will cause chocolate to seize. However, if you add even MORE liquid (cream, butter, even oil...NOT water) you end up with a sort of chocolate granache. The amount depends on the amount of chocolate. Just add liquid a little at a time and stir until smooth.
Sounds like you scorched your chocolate. Did it smell kinda burnt? If you scorch chocolate...throw it out...can't use it for anything, except revenge maybe...hmm??? lol
Rules of melting chocolate...
1. Heat VERY SLOWLY
2. Keep Stirring...let it heat up equally. Some compounds of the chocolate melt at lower temperatures than others...(cocoa butter melts at 98 degrees farenheiht....that's why it melts in your hand...) Also, a higher ratio of cocoa butter will give you chocolate that melts very smoothly. Most supermarket chocolate (read chips, bars, even some of the baking stuff) has an emulsifier called lecthin in it which will make it harder for the chocolate to melt.
3. Keep ALL moisture, especially water, in a galaxy far, far away
4. NEVER...EVER...EVER...EVER...you get the point...let chocoate get above 120 degrees Farenheit...otherwise it will scorch and ruin it.
If you are using chocolate chips, they will hold their shape until you start stirring them.
Now tempering chocolate...whole different ball game.
I find melting chocolate in the microwave very effective, providing the microwave temperature is set at medium, not high, or you'll have only-suitable-for-spearmint's-revenge. Give it 30 second bursts, stirring each time, it'll take about two minutes. I stir with a wooden skewer, as none is transferred to the spoons (for it to harden and me to lick off thus reducing the proportion I need for the recipe :P )
I find this a lot easier than the doulbe boiler method, as you have to be so careful not to let any moisture come in contact with the chocolate.