Casement window keeps freezing

WD40 will freeze. It's one of the worse lubricants to use in winter.

Your house appears to be too tight. Suggest you lower the humidity.
 
You probably have a curtain in front of you window keeping air from circulating creating a cold pocket of air. Make sure that the room. If there is air circulation on your window you will have less ice build up.
 
It gets too dry my skin becomes itchy and I can get nose bleeds if i lower it ...I keep it around 65%...

65 percent is insanely high for this temperature.

Should be about 35 to 40 max. You will have all kinds of moisture problems at that level.

There are charts on line.