in my line of business

I am a teacher by the way.

I think "work" works better than business:

In my line of work, being responsible is a must.

"Line of business" seems more product oriented to me.

Thank you!!!

However, if you are speaking about an industry that may have a lot of self employed owners, i.e. plumbing, carpenter, computer work, saying, "in my line of business" is perfectly OK.