Truly, it seems that consistency is everything when it comes to practice. The only way to practice is to practice and unfortunately that is indeed the best advice I can give. There are many strategies and tips on how to build habits and those can be massively helpful but the denominator is always the willpower to overcome your other desires and sit down to draw. Meditation has helped me with this a good bit but everybody is different. I suggest starting back up with an easy goal such as put a pencil to paper everyday. You can then build from there but it is important to maintain a very good consistency especially in the beginning when your habit is fragile and in its formative stages. Hope this helps a little, best wishes!