Fighting with an injury

Hey all. Happy Sunday.

I am fighting on the 13th of September.

I injured my shoulder and arm about 3 or 4 weeks ago. It got so bad the last few days I have broken sleep from it it’s like a nerve pain going from my neck to my arm. I went to the doctor and she gave me codein , muscle relaxers and anti inflammatories. I ran yesterday but it was tough with my arm. The pain medication helps a good bit.

Sorry long story short how do I prepare in the lead up. I will fight with one arm if I have to .

My friend recommended a massage. Any suggestions? Thanks 🙏