Sorry I can't remember who posted what and can't see the comments whilst typing.
I like to sleep cool. I have the window open and can't sleep if I'm too warm or have thick PJs on.
I have a long history of depression and anxiety from childhood but this has only been happening for the past year or so.
I've been able to control my really scary nightmares since childhood. For example if running away from something and I'm getting nowhere, I discovered when I was about 8, that if I turn myself round and run backwards I can run faster and get away. Once I turn round I usually wake up very quickly. If it's a bad nightmare I can usually wake myself up from it as I know I'm dreaming and it's not real. My children think that's really cool. My mum thinks I'm abnormal 
These are more like anxiety dreams with maybe nothing specific but a sense of fear and dread but once I wake up I don't tend to recall what they were about. Proper nightmares will really disturb me and upset me but these are difficult to define most of the time.
I did mention it to the GP in the summer as I thought my thyroid might be dodgy but all the bloods came back smack bang in the middle of the normal range. I was generally tired, more so than normal, muscle aches, weight gain, muscle cramps, feeling cold yet sweaty, hair falling out, dry skin, periods went haywire. Went on for months but has settled now. No cause found.
I will try some relaxing music/meditation things but have misophonia and get very irritated with any noises if trying to sleep.
Thanks for all the replies!