“Is radiotherapy worse than chemotherapy?”

It shouldn't be. Radiotherapy is when radiation is used to treat tumor in a specific location. Chemotherapy treats tumor throughout the body. Radiotherapy is used to direct treatment at or into specific tumors and often hopes to avoid the side effects of chemotherapy. That said it is not without its risks and complications. Often radiotherapy will be used at one location with chemotherapy used at the same time to kill disease elsewhere.
You should discuss this with your oncologist and radiation therapist.