Wow man sucks to hear. Gavin Hamilton is one example I can think of.
I've had alot of ups and downs with my bowling wouldn't say i've mastered everything by any stretch, but i'm still a pretty steady opening bowler nonetheless. I remember when I was younger when I seemingly forgot how to bowl and bowled about 10 wides in an over, will never forget that lol.
It was in 5th form when my favourite ever coach sorted out my bowling and i've been pretty swt since. When i'm ready to bowl I guess i'm in my own little box, i'm not thinking about what's going around me. I'm focused on doing every single thing right with my bowling.
Firstly, from the top of your mark all the way in try your utmost to keep your eyes fixated on the exact spot you want the ball to pitch. Make sure your head is up the whole time too, and try and stand fairly tall through your run in. This is all stuff that coach told me which seemed to rejuvenate my bowling.
Secondly I would say make a big effort to keep your non-bowling arm(front arm) up on delivery, every ball. This doesn't come natural to me so i'm often talking to myself to remind me to keep doing it.
Lastly with the run-in I can really relate to that because I often struggle for rhythm and have run-up problems. I would recommend a walk-in to your run or maybe some sort of hop or skip at the top of your mark, I find that helps me get into rhythm alot easier.
That's all I can think of, just think your teams given you this ball to put it on the spot and that's what you gota do. Not sure how much of this actually helps lol post how you go in this thread... I got 2/20 on Saturday

Haha