At the beginning of the year when I first started seriously getting back into chess I had a problem. Every game I played felt like I was fighting for my life. Every move my opponents made I would sit there and over calculate. Eventually over thinking it and playing the wrong move. Turns out the right move to play was the first thing that came to my head but hindsight is 2020 right? I would spend so much time trying to figure out the right move that by the time I finished a 15+10 game I would be exhausted. I'd play maybe one more game and that would be it for the night. Any mental energy I had just wouldn't exist anymore.
Things are a much different now and I credit a lot of it to a throw away Lichess account I have. One night I was sitting in bed and I couldn't sleep so I hopped on my phone and played a handful of games on Lichess. There was something fun about playing on an account where I didn't really care about the rating but I still got to play good chess. I did this more and more, eventually the act of just playing a bunch of games made everything click with me.
Another thing that really helped is playing blitz. I'm well aware that blitz doesn't do anything to help your game. I'm not tricking myself into thinking it's helping, trust me. The thing it does help me with is being comfortable with the chess as a whole. How are you supposed to improve at something if you're not comfortable with it? The act of playing short quick games lets me play twice as many as normal. Which in turn allows me to see more positions and get familiar with them.
Now when I hop on and play a 15+10 game after work it is no where near as exhausting and I can play way more games before I'm tired out for the night. It really lets me appreciate this game more than I was able to before. If you want to get good at something get comfortable with being bad at it. You can only learn by failing. Over and over and over again.