You should consult with a workers' comp attorney to preserve your rights in case you need medical attention for your back in the future. Once you have a workers comp case started, you can receive medical care and psychological help without cost to you. If you need to take days off and you get paid for them from workers comp, I doubt your company will continue to ignore the situation.
I don't want to assume, but did you report this incident to Human Resources or a higher-level supervisor? If not, then it will be hard or impossible to expect the company to take corrective action.
The other thing I would want to know is whether you suffered some change in your job at some point. Specifically, were you terminated, suspended, demoted, for example? If any of those things happened or there were other changes in your job which you believe to be significant, you may want to consult with an attorney. It is hard or impossible to determine if you have any kind of case from the limited information posted here.