Hate to tell you this, you've got to turn the screens off. I'm as guilty as anyone else, but if I pick up that tablet and start browsing in the early hours, I can kiss any chance of getting back to sleep goodbye.
Yes, thrashing around wide awake, trying to figure out where to put your arms while the sweat is streaming off you and your brain is doing 200km/hr trying to outrun a variety of demons is nasty. But if I decide I've had enough and do anything apart from getting up, having a cup of chamomile and reading a book for twenty minutes or so, I am doomed. I do find getting out of bed for half an hour helps, mad as that seems. It gives the pillows and mattress a chance to cool down if nothing else.
Years ago when I had to iron school uniforms and work clothes I'd do that if I couldn't sleep. At least something productive was going on and I found it unwound me enough that I could go back to bed and nod off. Another advantage, it was like the fairies had been in during the night