Psoriasis spreading after using cortisone cream

Hi I've had psoriasis dermatitis since 8, I'm 19 now and was diagnosed this year. I've tried many creams but what I noticed "worked" stopped the spread and minimize somewhat was when 4-5 years ago I was prescribed tretinoin for my elbows and knees. I stopped taking it so I still have some spots. But this year I was prescribed triamcinolone acetonide ointment 0.1% and I'm noticing my spots are getting smaller. Now I have darker skin and my psoriasis is a dermatitis form so it might not work for everyone. I also use skincare on it from amlactin lotion to the ordinary glycolic acid. I am now going to start using vitamin C 1.6% from medicube to reduce the darkness and marks.