Spend a little time each day in du'a/dhikr thanking Allah for what He has blessed you with, and ask Him to help you fill your time in a beneficial manner....Du'a really works. You'll feel better immediately when you put your trust in Allah, and then, of course, Allah is the best at taking care of our affairs.
Maybe you can make a list of things you always wish you had time but were always to busy to do (especially Iman related types of things).
Plus, eat some chocolate, exercise, eat your favorite food, travel, volunteer in the community, pick up a hobby, or what ever else eases your blues. By the way, don't feel guilty about having a vacation. It gives us time to focus on other things that matter, whether it is taking care of ourselves by just having needed rest or using the time for other interests.
Hope this helps!