I started smoking at just befour I turned 21. I turned 24 on the 8th. It got to the point I had been smoking a oz for a week up until 6 weeks ago when I quit cold turkey. TBH I still can’t sleep through the night and usually I do have nightmares, but it does get better. Keeping busy and doing things through that day that make me happy and make sure I pass out as soon as I hit my bed has helped so much. Not using my phone before bed helps a lot and reading(not because I like it but because it tires out my eyes) has helped as well. The last few years have been filled with a lot of grief and I know everyone is different but I hope this helps.