This is your choice, and your choice alone. Your teacher’s comments are about her life only, and how it has not worked out for her.
To determine whether you like elementary or secondary school, try volunteering in some schools to see what you prefer.
The beginning of a teaching career is difficult. First off is getting a job; then it is surviving in the planning, marking, organizing, management, etc. It is hard when you’re in the first time, but ask for help, use resources, don’t try to recreate the wheel, and know you’ll get through it. Once you start to get into the groove in what works for you, you’ll be fine. It’s just trying to find out what works, what doesn’t work, etc.
Good luck!
Teaching In Real Life 