I have the same issue. Too hard on myself, always stressing over things before bed. What did I do wrong? What is it I'm not doing, that I should be? How can I improve? It's difficult not to think on these things once I lay down.
Takes me a minimum of 40mins before I eventually fall off to sleep. But then the dreams begin and I awake multiple times per night (3-4 isn't uncommon), forced to then mull over each odd (and usually negative) dream experience.
It's a draining cycle. Very little true rest is ever had.
Not sure how to break it, other than working on my internal disposition during waking reality. Meditation tends to just make me irritable, but daily practice of gratefulness and adopting a positive mindset I think are potential avenues to alleviate the problem. I've been doing this lately and am hoping for good results.