I agree with Thea's comments it can be most frustrating, many a time my paintings have landed up in the bin, but i still keep going hoping to do a "masterpiece" next time!!!

So frustrating, isn't it. I've had a disasterous evening trying to paint - probably end up a bin fodder. Perhaps you are trying too hard to get it right. That seems to stop me in my tracks unable to progress. Try alcohol - everything is better after a stiff drink. Good luck and keep going.