breadstick, I'm a bad sleeper. I can go for three nights tossing and turning and getting up at the crack of dawn and then say for the next three nights, I sleep quite well! It's just my sleep 'routine' I guess. Maybe not sleeping well every other night is just yours now. Less sleep often happens as we get older too.
One of my friends sleeps for only 3 hours a night and is perfectly happy., maybe you are like her and Margaret Thatcher, that just dont need a lot of sleep as they get older.
Do you work ? can you have a lie in if you want to? Try reading and sewing , knitting anything you find relaxing , and don't get stressed if you can't sleep.
Do you have a close friend you can tell all the things that are on your mind, sharing often helps, have done it loads of times and works for me. x
try your GP advice, I tried some CBT exercises for anxiety and they were helpful for me.
Ummmm's advsie is good too, a relaxing routine each night.
I found listening to sounds that soothe me works when trying to sleep, for me it's the sound of the sea or rain. There are some usefuil free apps if you have acces to a PC or smartphone.