Will try to be reasonable short, always dislike reading wall of text with many grammar/etc mistakes.
I've been playing poker for quite many years (maybe 6-7 years full time, and few years before) and variety of games. From sng/mtts/2-7 to nl cash games which is my current game.
Pretty sure it was before but now I notice it much more often I feel quite anxious or stressed while playing poker. Especially first hour and last of my grinding day. My heart (likely) beat rate starting to increase, sweat more and so on and overall my head becomes really heavy. It is not always like this and not going all time (maybe 10-20 minutes after it goes away). I want to improve my winrate and to do so I need to focus better on my decisions and have fresh mind(head). I've noticed if I'm stressed while learning Spanish (thinking about other things all time) I do a lot more mistakes. Pretty sure same goes to poker.
Things which helping me: Meditation; Exercise; be patient and respect opponents(this two are super hard); setting goals, not checking results, have positive mindset....
Things which likely stress me and overall bother a lot: Mistakes(decent EV blunders), Real life problems, downswing, lose to other players.