B2b calls drive me into semi-depression

I’m absolutely pleased with the company I work for. It’s a great place to be. However the call volume makes me want to throw in the towel some days. I’ve been going strong for 12months now in Services and I’m starting to dread logging in most days. Its possible that I may be experiencing burnout from the constant repetition and high call volume for extended hours at a time... I’m scared that I might mentally check out and hurt my metrics. How can I stop this feeling and cope with the job better?