regarding the shoulder pain, you may have injured the rotator cuff. I did mine , both of them, from different falls. One healed completely and the other did not, and probably will not. But the one that healed, it took a year to heal . A year. So, don't despair. Some of these ailments might pass.
I am currently having trouble with one knee in my dressage saddle and somewhat in the Western saddle too. I don't think this one will go away. It's just part of being middle aged. but you have a lot of healing power. Just don't want you to feel too discouraged about it.
Also, if you are pulling that hard on your horse to control it's speed, then he/she needs some work to reeducate her on the meaning of pressure on the bit. That's a whole 'nother subject/post, isn't it?
Let us know you you are doing and we hope you will heal soon.