Tell your manager to increase your work- load just a little bit at first. Once he sees how efficiently and quickly you complete the assignment, he'll be happy to give you as much as you can handle. Unfortunately, some managers are never going to delegate. If you're stuck working for one of these monsters, changing jobs may be your only way out. Take on different work.
People joke about being stuck in a rut.
But it's no joke. Life shouldn't be a grind. So if you feel stuck in a rut, get out. Break your daily routine by doing something new. For example, if you've always wanted to write but never tried to do it, volunteer to write an article for your house organ or a trade journal.