Restless running mind can't concentrate . Advice needed

So I had some traumatic experience earlier this year, it's been months I can't concentrate properly I have micro flashbacks of anything from anytime, then I get anxious or I start to daydream, frequency has no specific patterns or no order I would think of a research project with mentor then suddenly start thinking of certain words someone said 1 year back, then have random flashbacks of a certain night, I would then have random images and words running in my mind, then suddenly I'll jum to anything else so random like a pokemon episode. it's like having two minds one is always restless and running I want to concentrate on studies any advice to increase concentration and decrease these random flashbacks and daydreams. I see have great concentration span of 6 hours continuous .