Hi Guybrush,
To reassure you....... Your grade is only one part of your ability to be a great Physiotherapist. I agree with Choccy_21, getting a First in a Physiotherapy degree does not necessariy mean you will make a "better" Physiotherapist, nor does it mean you are more likely to get a job. Prepare well for your interview by writing lots of "reflective" statements, have a good CPD folder, think about the questions you might be asked and be open-monded about your strengths & weaknesses. Interviews are objective and are marked on a strict criteria so stay positive!
L