New LMT client feedback

I’m feeling a bit discouraged. I’m extremely hard on myself, that’s just how I am as a person. I just graduated and started my job at a spa last week. I’ve had all good reviews so far and even a rebook, but my boss called me today about one clients feedback. The client said she didn’t feel like I focused on the parts she asked me to (her lower back, shoulders and hands/wrists). I felt like I split the time between all of those equally. My job is only part time and I’m starting my own business also. I’m struggling with some imposter syndrome and self doubt even though I get majority great reviews. I guess I’m looking for advice on how to be more confident in my abilities as a massage therapist