Is it okay to quit a job because of being too tired?

I've been working at this tech company for 6 months and I'm about to quit after being burnt out for 3 months. My salary and working hours are normal. I just feel tired all the time. I sometimes don't even have the will to do certain tasks, but once I start doing them I get in a flow state and enjoy doing them. But mentally I just feel really tired. <br><br>I feel guilty quitting the job and not being able to work but is this a valid reason to quit a job, being exhausted without any reason?