Without even noticing it it's easy to fall into being fed up, bored, or negative in some sense towards music because you aren't making the progress you'd like to make or any number of similar reasons. One of my producer friends seems to be the epitome of this, he's completing a track a fortnight at one point then hasn't made any music for months at other times. It's important to constantly be asking yourself a number of questions about your attitutde to making music, and if you notice your attitude becoming negative than you neded to remedy this. Firstly, when you go into a production session what is the specific goal of that session? If you have a vague notion that "I haven't finished a track in ages, I better get one done tonight..." then you aren't going to get anywhere. Finishing a track entails completying many different tasks, set just one task and you'll feel as if you are at least making progress. Say to yourself that you're going to finish programming a drum section, write this down if you need to. I have a whiteboard system for this purpose that i'm currently using for this and it works great.
Secondly, don't treat production as a chore. I'm guilty of this, certain parts of completing a track are less fulfilling than others. I'll go a few days before feeling like I have to do some work on a track, meaning that I go into the session with a negative attitude. Its at this stage that it's important to remind yourself that it's really a privelage that you get to sit down and be creative, and that you really can do anything that you like. A negative attitude means you won't have an open mind and any happy accidents you treat as mistakes. In short, you're censoring your ideas before they have a chance to develop. Thirdly, experiment with new techniques and try new things. Part of the reason production can sometimes fee like a chore is that we are using the same old tired methods, the same old VST instruments and the same old effects, leading to a predictable result. Push yourself into new territory and the novelty of a different method will sustain you through completeing the track you are producing.
Finally, set a minimum amount of time. Sometimes we don't make progress in a session until the very end. Or even worse, we quit just before we are about to make progress, with your next great idea right over the hill. Thats then wasted time that could have been converted into useful time by just sticking at it for another half an hour. So set a minimum amount of time and work quickly. Be honest and discard musical idas that simply don't work quickly. As we all know making music can be difficult and it's all to easy to make poor use of your time. Implement some of these rules and hopefully you'll be able to enjoy yourself more and make more progress.