Everyone gets bored or frustrated with a project now and then.
I used to make myself finish, but that takes all the fun out of it! I decided that, Hey, this an art. Why am I pressuring myself? If I have 20 different things going, and I get a burst of inspiration for one, I switch to that! It is very liberating to "go with the flow" and not be my own task master.
Relax and enjoy yourself!
If you really hate it - put it in a box and forget about it. Read a good book and don't work on anything if your block is really bad!
But have fun!