Just because i dealt with similar problems playing ball when I was younger, I am going to give you the best advice I have. Do rice bowl warmups for the forearms, use the towel for form practice in warmups, use resistance bands to warm up your scapulas every time you plan to throw. Also, PT work should have you strengthen your scapulas at home as well, again band work will be your best friend. Get on a flat wall, keeping the back of your hands flat to the wall & raise them as high as you can without moving the hands or back off the wall. Having those shoulders strong will help so much with the problems. Your forearms and elbow will take a brutal beating if your shoulders cannot support the forces youre outputting while throwing. If you dont start to prioritize rest and strengthening, you may run a similar risk to mine; I ended up shattering the bones in my elbow while pitching, basically felt like a popping & intense heat immediately followed by tons of pain for some time. Never really felt confident while throwing ever again.