New Job Guilt Trip

So I got a new job and I’ve been doing everything to be perfect. I show up early, finish all my trainings ahead of time and schedule myself for every hour that they need filled. Today I had a online training course and I swear it was from 10:30-11:30 but it actually started right at 10:00. I called and apologized and asked to please be rescheduled and I got chewed out hard core. I already feel bad enough as it is, but my boss was like now everything is held up because of you and now we have to do special accommodations. I didn’t ask for that, I was just being honest that I had my time wrong. I don’t know what to do. I feel awful.