There are several signs to know that you are unfit for project management:
- You are disorganized, by nature
- Your mail client gets more and more emails in and not much out
- Most of your email messages are still not read - and you're not reading as much as you're getting
- You don't have people skills
- You think that project management is giving orders to people
- You think of team members as resources with no feelings
- You're doing project management just because it pays well, and not because you like it
I think there are many other signs as well - but the ones above are the ones I was able to think of at the moment.