I am at no means a law expert. I believe discrimination is hard to prove when it does not involve a protected class (race/sex/religion/orientation).
It is typical for leadership to sweep things under the rug. First and foremost they don't want to deal with it and its paper work. So basically they pass it off by saying you two will have to work it out.
I would first document all matters that you were directly involved. Never report someone elses accounts, or your feelings, guesses, or rumors you heard. Keep it factual. Gather witnesses.
The Hotline is a good way to report serious workplace matters. But it can also be used to bite you in the ass when it involves leadership.
Being a medical issue it may fall more under workplace bullying. At first all they can do is confront the TM about what he is doing. If it continues, I suggest you request workplace mediation with the your STL, area ETL, and ETL-HR on the matters. This is a open discussion that will allow you to vent your grievances. I am not sure of Target's policies on it, but it may be documented. So if the TM still continues after this, your store leadership can move better on disciplining the offending TM.