You might be responsible for creating the only environment in which they are talked to in a respectful way, as a mature developing adult, on equal par to you in terms of dignity.
You can TALK yourself into being a more effective teacher. Believe these 3 things in order to be more confident each day.
The boundaries you're uncomfortable enforcing are the very same ones that they NEED because the chances are, they aren't getting them elsewhere from the other people in their lives.
When discussions take place around 'curriculum', you can't ignore the fact that getting behaviour right is an integral part of it.