I used to have a horrible time getting to sleep too, and then would feel exhausted and groggy the next day (only to repeat the experience when it was time for bed). Here are some things that have made a huge difference for me:

1. I cleaned up my diet (ok, still a work in progress, I backslide from time to time). The biggest thing for me is - chocolate. Chocolate contains theobromine, which is like caffeine, except longer acting apparently (it's described as having a "more gentle" curve - i.e. it takes longer for you to feel the full effects, and longer to get it all out of your system, unlike caffeine that peaks and dissipates quickly).

For example, I was sleeping well with no chocolate. One evening, as I was cooking dinner, I had 2 squares of dark chocolate while cooking (~7pm or so). Boom. Couldn't sleep. I felt completely AWAKE and alert, very late into the night. When I tried having chocolate a little earlier (early afternoon), I was able to fall asleep, but it was incredibly restless, and I was still exhausted when I woke up.

I give myself one cheat day a week, usually Friday or Saturday, when I can sleep in the next day. Other than that, I try to avoid chocolate and sugar, and it helps. I also don't drink coffee/soda/caffeinated drinks, I imagine they'd also mess with your sleep, especially if you are (genetically) a "slow metabolizer" of caffeine.

2. Sounds goofy, but the sugar/chocolate alone wasn't actually enough for me. I made my room totally dark (I cover up alarm clocks, any other light sources, and have light blocking curtains on the windows, with velcro holding them to the side of the window frame!)

Then, about 2 hours before I want to sleep, I get off all computers/tvs, and turn off all the lights in the house - and use an orange light in my bedroom. (I got one from my local Home Depot for ~$5, and it plugs into a regular lamp, I just replaced a light bulb in my room with the orange bulb.)

Blue light (any light that is white has blue in it, and computer screens, phone screens, and TV are really bad for this) can stop your body from creating melatonin. Your brain gets the signal that it's still daylight - and tries to keep you awake.

I hang out in my room, do exercises/stretching, read, listen to music, and generally relax. (Sometimes I use orange glasses that filter out blue light to get on a tablet or watch TV, but this isn't perfect, and I don't recommend it when you're first starting out!)

The orange light doesn't do enough, by itself, to counteract the chocolate for me. But together, they work really well!

I was at the point of thinking I had a serious disorder, I was falling asleep during the day (I work from home!), unable to think clearly, unable to process information - and unable to fall asleep before 2-3 am (sometimes later). I was chronically exhausted, and those two things really seem to fix 95% of the problems or so I have.

I still have problems with backsliding (chocolate is addictive!) and extreme stress (therapy, trying to process crappy childhood stuff) can throw me off. But seriously, the difference is insane. I had sleep problems my whole life, and really thought there was something wrong with me. Nope, I just can't process the stimulants in chocolate fast enough to get to sleep, apparently (and need non-blue light to make melatonin to get to sleep!)

Good luck!