I don't think anyone's questioning whether your team leader is abusive. What I think everyone here is asking is, why do you continue to see an abusive team leader?

I imagine there must be a reason you have to. But I honestly don't understand the situation either: why you can't find your own therapist, why your team must manage your meds, why you can't change teams since you say you've never had a problem with another team, etc. Since your mother is involved and agrees with your assessment of your team, I assume you have been required by law to see this specific team with this specific leader, else you would switch teams within the same institution. Why must you see this person specifically? And why must your team choose your therapist, rather than you choosing a therapist for approval by your team? Does it make sense to involve a lawyer?

From an outsider's perspective and with only the information you have given, it looks like you have a variety of other options that you are not pursuing, and so it looks as if you are continuing to see someone who abuses you despite having other choices. If you explained why you have no choice but to associate with this specific person, that would help a great deal.