This is my first year since reverting to Islam where I was able to attend and participate in activities of Muharram. While I understand and feel the grief for Imam Hussayn (as), after the majalis and lamentations, when the matam started I felt almost a sense of shock. It felt wrong and inconsistent with what I understand from the teachings of the Prophet (pbuh) and the Qur'an. Previous to that, I felt very secure in my decision to follow the path of Ahl al-Bayt, but admit that the experience and then seeing images of tatbir as well during this time has shaken my belief somehow. I am not sure if the culture in which I have grown up (US) and its norms for bereavement are in such contrast or if it is something at a deeper spiritual level that has lead to this unease, but I am very troubled by the impact it has had on me.
The main point is that you believe and feel grief for Imam Husain (AS). It is a condition for every believer to love the Prophet (SAWA) and his Holy Progeny Ahlul Bayt (AS) more than loving himself and his own family.
The way how to express this noble feeling of grief and sadness depends on you and your culture but it must be within the frame of Islamic rules
You were brought up in USA, so you may not be familiar with the Matam practiced by your brothers in faith who came from the Indian sub continent or other countries. You wrote that you felt wrong on seeing them. This feeling does not make you away from following Ahlul Bayt (AS) as far as you believe in Ahlul Bayt (AS) being the Most pious leaders of Islam after the Prophet Muhammad (SAWA) and you feel grief for their tragedies.
Islam as the religion for all human beings, gives all of them the choice to express their feelings according to their own different cultures and ways as far as it remains in the frame of Shariah.