How can one deal with people's harm and insults due to appearance, knowing that one possesses good character and religiosity, and considering wearing the khimar to confront this, despite having difficulty breathing?

It is recommended not to pay attention to the words of the idle and to rise above their insults, following the saying of Allah the Almighty: "And the servants of the Most Merciful are those who walk upon the earth easily, and when the ignorant address them, they say [ woorden van] peace." It is also recommended to maintain remembrance of Allah (dhikr), connection with Allah the Almighty, and the Qur’an, for it is a healing for what is in the chests. As for the niqab, it is obligatory for a Muslim woman if it does not cause harm, and this has been detailed in previous fatwas.