I could go into a lengthy narration of various thoughts regarding your experience, your pitching coach and such, but without knowing more, I’m not.
So, regardless of who says what, shut down and seek professional medical advice on your condition. And just a thought for the future, you’re not in the company of experienced professionals who train, coach, and manage pitchers. So you have to be somewhat instep with what’s best for you and why.
Once you have a professional medical examination - take heed from that point on to take charge of your own well being on the field. I say this because pitching is a demanding test of the human body to continually do the same thing, over and over again. That body of yours requires more than just “advice” from high school coaches. You require guidance from your medical professional on your problem, HOW NOT to get into this situation again, and most important, don’t be hard on yourself that if you don’t do what your asked to do pitching wise - not training wise per your past and existing medical issues, you’ll be cut from your club or sit on the bench most of the season.
I know this is a lot to ask of a 15 year old. In that regard, there are those on this web site that can offer advice, solid advice on ways to go about this, that work in your favor.
My compliments to you Ramon for knowing enough to ask questions and seek out suggestions. Very gutsy thing to do.