What is dual personality like? Am I a dual personality?

The dual personality you mentioned is a very serious mental illness, which is extremely rare. It is important that patients have a separate experience, that is, they have two or more feelings about the world. Moreover, two personalities are two people, and in the process of personality alternation, there will be consciousness disorders (such as fainting).

From your description, you can't be sure whether it is a dual personality, because the two states you describe may appear in a normal person. And no symptoms of mental illness.

In fact, each of us has to wear different masks in social life. Sometimes we cater to them, sometimes we are independent, and sometimes we are cheerful ... When we pay too much attention to these States, we may exaggerate their influence and have the illusion that something seems to be wrong.