棘手

This is tough work. / This is a thorny job. / This is really a hard nut to crack.

The lack of a licence was pinching me.

handle a touchy/sticky/ticklish situation

knotty/thorny problem

delicate negotiations; negotiations of delicacy

troublesome state of affairs

thorny issue; touchy business; matter of delicacy

feel prickly about sth; feel a delicacy about/in sth