Is it a bad idea to use tooth-whitening rinse if i have sensitive teeth?

Yes: Sensitive teeth can become more sensitive with tooth whitening rinse, gels, etc. See a dentist to resolve the sensitivity and they most likely will have a low sensitivity solution for whitening your teeth after they resolve your sensitivity.

Yes.: Tooth whitening products based on peroxide bleach have a tendency to make teeth more sensitive. If your teeth are sensitive before you whiten, they will be more sensitive afterwards, and because whitening confers only a temporary benefit, repeated whitening will necessitate revisiting this problem again and again. You should explore other whitening options with your dentist, including veneers.

Yes!: Whitening toothpastes and rinses are both known for causing sensitivity in people who don't have it to start with. I would think it's even worse for those who are already sensitive.