When do you feel locked in? Is it a luck of the draw kind of thing? Or a mechanics/alignment issue specific to your game?
There are some days I feel on fire, and others like I can't hold the bloody stick. I'm not the kind to blame mechanics/alignment for mistakes, and I've been playing cue sports for such a long time that I feel quite level-headed about how I approach that aspect, though I do occasionally get caught in that wormhole (Not so much now, and I feel quite switched on about the amendments made from my cue action when playing snooker/have had some good heads around me for advice in general). I am pretty sure most of the time the issue is shot selection for me, and then after that, the doubt that follows in every other shot.
When I started playing was primarily to avoid be at home during a break-up, so was playing everyday and taking a lot of positives from seeing progress. Was good 'mindfulness' activity for me, and helped me meet a lot of new friends. External stress has had both positive and negative effect for me at certain times. When you've got calls and texts about important issues taking away focus it's horrible, especially when playing for a little 'something'. But work, or social stress, I love putting that shit on silent and generally can see the relief filter into my game lol