Think twice about caffeine and consider stopping it past, say, noon and see if that helps.
Also, get aerobic exercise (walking, hiking, jogging, biking, cleaning, etc.) but no more than maybe 1 - 2 hours before bed.
If it is stress that is bothering you, you will need an outlet for that. Exercise can help. Making art or talking to a friend can, too, but don't hesitate to talk to a professional if you feel the need.
Also, consider your sleep environment. Is it dark? I mean really dark, like stub your toe because you can't see where you're going dark. If not, then invest in blackout curtains. If your mattress is uncomfortable, see about flipping it and, if that doesn't work, consider replacing it. Keep your phone out of your room if that is at all possible, and don't watch TV later than maybe 1 hour before bedtime. And keep your bedroom a few degrees cooler than you would normally want during the day.