I’ve always been this way, but every so often I still have trouble turning my thoughts off enough to get to sleep.

There’s a technique I use on those occasions that helps a lot. Basically, just try to imagine a shape - it could be a circle or a sphere or a triangle or whatever - and just try to rotate it in your head. Pick a colour too. Try to keep it going. Any time you lose focus because another thought takes over, try to get the shape back.