At the risk of sounding like a broken record, when it comes to extrinsic-motivation, it really comes down to finding outside sources to inspire you. Practicing with others (just like studying together or going to the gym with others) really does help. I can't stress enough the importance and value of being in a community. This is the very reason why Tonic exists - a (free) way to practice with others in a supportive community. Give it a try today and let me know how it goes :)