hey man, we all come across the bad times of building- i've still yet to complete a build! most of the work I've done has been wrong and I wasted materials due to being hasty and mistakes. But it happens, that's normal with building, you make mistakes, you get angry, you get frustrated. Don't give up, take a break, let yourself relax then come back to it.
Please don't stop building, all your work has inspired me to keep going and try to get my ones finished.