They won't be put off by psoriasis. There is nothing to be ashamed of or embarrassed about. You didn't do anything wrong. Skin disease has no meaning other than what it is, even if other people attribute odd things to it. It is natural to feel anxious, angry and depressed.
Friends can help.
People around you can be very supportive. You can help your friends support you by letting them know that psoriasis is not contagious and that it's the result of skin cells rapidly reproducing.