I think what you are asking is not how to be more motivated but how to work much more than 40 hours a week on a regular basis, namely on your 9-5 AND your perso

I think what you are asking is not how to be more motivated but how to work much more than 40 hours a week on a regular basis, namely on your 9-5 AND your personal projects... if I was you, I would be very careful not to overload yourself and quickly drift into a burn-out! Just because it's projects you might actually enjoy more than your 9-5 does not make it easier on your brain and body - it is still mental work, it is still sitting at your desk and it might even be more challenging then your 9-5 because you are likely working on mostly new things. I think what you are experiencing, being reluctant to work more on your personal projects, is your body telling you you are tired and should be more worried about resting and doing something completely different. And set time outside your 9-5 days for your personal projects, why not focus it on the weekends or start a 4x10 schedule and use the Friday or Monday for personal stuff?