I also find it a little suspicious that you have narrowed down your type to either EII or SEI. Because if you can't distinguish these yet, then you obviously have more to learn, and then it could be that you are some other type.
So for example why do you think you are an introvert? Introversion means that the information itself is coming from the subject. In the case of Se vs Si, extraverted sensing is direct sensing of the object. In the introverted case the sense perceptions are colored by the unconscious (the subject). But it's really hard to be sure about this unless one already knows the type.
I'm not saying you're wrong. Maybe you are one of those types. But have you considered IEE? They frequently identify as introverts.
Have you watched videos of EII, SEI and other types?
