"Writing is easy. All you do is sit staring at a blank sheet of paper until the drops of blood form on your forehead." Gene Fowler
But if writing is consistently that difficult, then something needs to be changed.
Yes, writing is work. But unless it's fun, too -- at least a good part of the time -- take a closer look at what you're doing and what you can change in order to get the fun back, so you don't have to sweat those drops of blood day in and day out.