The best way to motivate your boyfriend is to remind him of the reason he is working so hard. If you don’t know, ask him. Also, make it a regular habit to remind him of his goals whenever he feels discouraged. It will help him to remain focused on achieving those goals.  You could also motivate him with a looming reward, such as the promotion he’s waiting for, a vacation he’s looking forward to, or even just the weekend that is a few days away. It’s always nice to have something worthwhile to look forward to in a difficult situation.