Wait! 55 degrees leaving the evap in the suction line and your getting ice at the compressor? Well then we can safely assume 32 degrees or colder at the outdoor unit if ideed it's frosting.
Since you cannot have a temperature loss of more than 2-3 degrees in the suction line in a properly operating system you must have a suction line restriction or you're boiling off a pile of liquid stuck in the accumulator. (is the frost between the accumulator and compressor? If so, maybe your accumulator's oil return port is plugged). The suction line, as you mentioned, is superheated by 13 degrees leaving the coil. No liquid present. That said, how could it be freezing outside unless the refrigerant is changing state, condensing and remetering?
Again that leaves, assuming the info you gave is accurate, a restricted suction line and no other alternative.
You are not flooding the indoor coil if you have that kind of subcooling and pressure on the head side and had weighed the charge in. Just so we're on the same page there are 16 oz to a pound.