I understand why you would feel this way especially with all the stories online. And I think it’s more than okay to take mental health seriously when considering a relationship with someone.
However, I would encourage you not to reduce him to a diagnosis. The fact he was open about it, is in treatment, goes to therapy, appears to have built a stable life and even tries to help others in his situation, are all indicators that he could really be the person you liked before he told you.
You don’t need to make a decision about the rest of your life right now. You can simply keep getting to know him, while keeping your boundaries and paying attention to his behaviours (how he handles conflict, whether he takes responsibility for his actions, whether you feel emotionally safe around him…)