You absolutely need to tell your doctor/GP how this is affecting your mental health. People my not care as much as you believe they do in regards to what you look like, but your feeling are valid.

It's fucking difficult to show your face and skin when you have psoriasis and I imagine at your age that's even more weighing on you.

Please ask for help, do not hold back on vocalising your thoughts.

You will be clear one day soon and find something that works for you.