Neither am I, but you're certainly bordering on crazy in this case.
The MBTI is a highly useless personality test, as personality tests go. The test claims to measure 8 dimensions of personality but according to factor analysis it actually only measures 5. Over time people can go make a radical transition from INFP to ESTJ, and for most, personality does not change this radically. And lastly it tells you essentially nothing. It was trendy in the late 1980s and early 1990s among business types who are particularly susceptible to crack pot crazes.
Introversion is much more than social withdrawal. I'm a typical introvert, yet I'm extremely talkative. I don't have many social fears. Still, I'm inside my head a lot, I need my own space and time to recharge, I have an inner life, I'm never bored inside my own head and I don't need a lot of external stimuli.
You sound a lot like me, except I hate sitting around doing nothing. I feel like I've always gotta be doing something, otherwise I get bored and frustrated. And I don't get upset when I have to go somewhere. I like getting out and about occasionally. It gets boring staying at home all the time.