Wait for a good moment when you are in the mood. Or remind yourself regulary what will happen if you don’t i.e rubbish job prospects, no promotion or lower income status.
I personally come on here and link up with as many people as I can, and when I read/hear about how they are preparing, I am motivated. It is hard to self-motivate, so definitely reach out to others and see how they are preparing and that should do it! It works for me