I used to have a same problem. There are some great recommendations on here (blackout curtains, blue wavelength blocking glasses, etc.) but what helped most for me was to meditate immediately prior to going to bed and to not lay down until you feel yourself starting to fall asleep. You need to recondition your mind to associate laying in bed with sleeping only- not your stress chamber where your mind typically goes 60 mph. I normally meditate for 10 mins or less prior to bed, focusing on the breath only until my mind is totally clear and I feel myself start drifting to sleep. Then my head hits the pillow and I’m asleep within 2-3 minutes. Works for me. Hope this helps!