We are at
Praxisgemeinschaft Oldesloer Straße in Schnelsen.
Schnelsen is not exactly central, so depends where you come from.
Anyway, the doctors speak English, at least I know that Dr. Fricke, Dr. Missal and Dr. Bittmann speak English - problem might be with the PA's, I don't know if they speak English, but there's quite a few of them, so there should be at least one or two with who you could make an appointment without speaking German.
I highly recommend this practice, especially Dr. Fricke.
They are not the type who just prescribe antibiotics for everything, they always try to use less invasive medication, generally not too much chemical stuff. They have 3-4 general practicioners and two specialists for inner medicin. 3 of them also offer psychotherapy, I know that two of them also offer acupuncture.
For the general practicioners you can just go during their consultation hours without making an appointment, for the inner medicin you have to make appointments.
Downside is that you have to be really patient, waiting time is generally very long - that's because they are really good, so they have a lot of patients.