Simply ignoring your feelings to get a job done is just a tactic, and IMHO, not a very good one as it is not sustainable. You should always want to do what you are doing; not necessarily in the sense that this is what you would like to be doing for the rest of your life, but in the sense of recognising that this unpleasant task will get you closer to that something you would like to do the rest of your life.

I think the best method to get something done is to first have a clear vision and passion for the bigger picture. Then, understand how this unpleasant task gets you nearer to the goal of that bigger picture that you want. If it does, you won't need to ignore your feelings. On the contrary; your feelings will push you to do it. If it doesn't, there's a good chance you should be doing something else.