Whatever project I worked on, being it work related, or a DIY job at home, modelling, or studying music; there invariably comes a moment you just want to quit and give it up as a bad job.
Very rarely it ends up in scrapping the project, more common is to take some time off and think, really think and have some sleepless nights over it. Most importantly and rewarding though is to discuss the issue with knowledgeable people. You will find a way forward and in due time you will be able to surprise us with a beautiful (completed, of course) WBII.