About relaxing... Running does it for me. Perhaps I've replaced one addiction with another but is a hell of a lot healthier. I put on my Ipod and just run and I forget about everything and everyone I just focus on pushing myself and met feet hitting the pavement and the way it feels just to get lost. Give you a high that's a hell of a lot better then any drug ever will too. A natural high, really happiness not that fake stuff.
Maybe something like running will work for you? Biking, swimming, painting...there are tons of options. Just something you can get lost in. Something that can just make you forget about things for a while. For me that's how I used alcohol.
About sleep-- Yes it is very common to have issues sleeping. It took my several weeks to get used to sleeping without a nightcap (or 12) and once I did it was such an amazing night sleep! Seriously you forget how great natural sleep makes you feel! And how amazing it is to wake up well rested and not hung over.
You will get there. In the mean time just lie down whenever you feel tired, if you can. Sometimes I found it easier to grab a nap after work or in the middle of the day on my days off because there's less pressure to sleep then.
I also was given an IPAD by my company and it has this great App called sleep pillow. They're on IPHONE's as well I'm sure (I don't have one of those but I think it's all the same Apps) but any kind of sound machine or or actual sound machine might help. The sound helps relax my thoughts and drowns out noisy neighbors and the constant sirens on my street.