I hate it when that happens. Waking up early morning and not being able to go back to sleep is the worst! When that happens to me, I usually end up going to work early and just taking off early as well. It's hard to find something to do around the house at 4 am lol. Sorry I don't have very good advice - I've taken NAC before as needed, which helps with bipolar tendencies, although I find it to be kind of energizing, so probably not what you need here if you want to sleep.