I failed it at MEPS as well, couldn't get past line B either. My Reserve recruiter had me drive to the nearest base for an appointment with the med group, where I did basically every eye test you'll end up doing at the FC1. Was able to pass depth perception there due to having more time with it, less stress, and an examiner who gave me some tips (wiggling your head and trusting your gut got me a long way through it). After passing there, I was back on track to my FC1.
Don't sweat it, I stressed too much about it but you'll get through eventually.