Baja_Costero said:Definitely rotate the plant in the meantime if it appears to be leaning toward the light.
DaisyI said:It may be too chilly. I just looked at the website where you purchased your plant. Four things stand out: keep it warm, water sparingly, keep it in bright light, use cactus appropriate soil.
DaisyI said:Have you looked at the white spots with a magnifying glass?
DaisyI said:Hopefully your plant is suffering from the shock of leaving its nice warm greenhouse for your chilly window. That happens with greenhouse grown plants. Do as Baja has suggested: no re-potting, very little water until you see signs of life next spring. If the trunk is solid, your plant is still alive.