It appears you are in a cycle of events, one leading to another and bearing down on you.
I suffer from the same problems, and has been worse the moment the clocks went back last year. I use a sun lamp each morning to give me some daylight, they are called SAD lights for seasonal depression.
I get so tired at 6pm I have to crawl upstairs to bed as I feel cold, cannot concentrate or read.
This week I have changed things around, each day I have been for a swim, eaten light foods and not had caffeine and spent a few hours in the weak sun in the garden wrapped up under several coats and blankets.now it is 6pm and I really feel quite calm and not at all tired.
Will try the routine again next week, and see if it helps me.
I wish you luck, keep strong xx