You may end up needing surgery, but of course you don't want to go there first. So, FWIW, I'm a physician but not an orthopaedic surgeon. I hope I can help here, and I realize you may already be doing much of this. I don't know you, so maybe some of this is irrelevant--ignore if not needed, keep if helpful. I'm sorry you are going through this.
Before this injury becomes chronic, throw the book at it. Do everything simple and harmless you can do right now that is not surgical: rest from aggravating activities, ice after activity, green tea, turmeric with pepper, and ginger as anti-inflammatories. Eat super healthy food, building your diet around plants. Check out some information on anti-inflammatory diets. The more white sugar, white flour, and concentrated animal fats you can eliminate from your diet, the better you are going to feel, and that goes for everything, not just your shoulder. Exercise is a powerful anti-inflammatory, so since you can't play ball right now, find something else you can do daily, if you aren't already. At our age, you don't have to go at it hard or fast or far. Consistency is much more important. Get adequate sleep. Manage any other medical problems optimally. Don't let anyone else stand in the way of your doing these things and getting well.
If you can tolerate them and your doc says it's OK or thinks it may help, also go with the topical anti-inflammatory lotion (diclofenac) or oral nonsteroidal anti-inflammatories (any kind) for a couple of weeks.
As someone correctly mentioned above, you need a physical therapist and a very competent massage therapist who really knows their stuff. Your doc may be able to help you find them. Learn safe stretches and exercises from them, working up very, very slowly. Give them feedback and let them work with you on modifying exercises and activities as necessary. Get them to communicate with one another so they all know what's going on with you. Acupuncture will not hurt anything, and I would try it. Obviously it won't alter bone, but they may be able to calm the nerves and muscles down, which might be enough to stop things rubbing against the spur. I've gotten a lot of mileage out of these different non-physician healing arts and simple exercises. For example, I'm swimming with a torn subscapularis (it's been torn for over 40 years). I'm not a swift or powerful swimmer, but that's not my goal. I'd rather stretch and go in for massage tweaks than have surgery, and so far it's working.
Just be sure the people you are seeing have some kind of license and that the treatments proposed have some basis in the medical literature (not on a bunch of dotcom sites). There is a lot of voodoo **** going on out there. Ask a lot of questions and be willing to spend time identifying some good people. A competent practitioner will not interpret your questions as a challenge, but will welcome them and encourage you to be an active participant in your own healing. Of course, none of us has all the answers, and we should admit it when we don't know something (which is often because no one knows it).
Set some reasonable goals. Your first goal is to do the stuff you have to do without excessive pain: eat, get dressed, wipe your bum, carry groceries, put your dishes away, put a seat belt on, drive a car, etc. Your second goal is to be able to do stuff you want to do, like toss the ball around. Please keep in mind that this might be all you get. You're not going to feel like you're 20 again. It's not going to be perfect, even if they operate on it. I know that seems obvious, but it's unbelievable how many people think that surgery (or whatever treatment they are pursuing) is some sort of magic and will restore 100% comfort and function, and they are very disappointed when their results are only partial. If you do end up with surgery, the rehabilitation exercises will be very important.
The steroids you inject into a shoulder (or anywhere) generally either work pretty well the first time, or they never work. Repeated injections may provide diminishing returns. The steroids, if used repeatedly, may cause the ligaments, tendons and muscles to atrophy, so please do not do these injections over and over.
I hope this helps and I hope you feel better soon. BTW, don't be afraid to shop. If you encounter a practitioner of any sort who is not listening to you or serving your needs, move on and find someone else. Don't worry about their reaction. Your health is more important than their feelings.