I know how frustrating that is, and I sometimes have the same issue. A few things that have worked for me are reading in bed until I (hopefully) get sleepy again, playing public radio or podcasts softly until I get sleepy, or write down in a journal what's on my mind and what I'll do about them tomorrow, then try to go back to sleep. I do all of these in bed with a very low reading light. It's often recommended to get out of bed when you can't sleep, but I've found that that wakes me up more and I just feel more rested in the morning if I've been in bed most of the night. Any reading, radio or podcast content needs to be interesting enough to distract me from my thoughts but not over stimulating. I don't know how much sleep you're getting or how old you are, but if you're older and getting 5-6 hours, you're probably getting the minimum you need. Of course, the immportant thing is how you feel during the day.