Lichenified plaque psoriasis flexural

Hi All. I am hoping someone might be able to help me with my diagnosis? Here is my story- cut short. (Ish) After giving birth to my first child I started with a very itchy anus. Many doctor visits later and a change of doctors, I found myself having a sigmoidoscopy and having a small op and 2 polyps removed however nothing helped and it started making my life hell. I was awake all night and in so much pain. Many years later, I still hadn't had a diagnosis or had a break from it unless I was on steriods but started to learn to live with it. After my second child I started with scalp psoriasis ( still the docs were ummming and arhhhing whether it was or not. I started using more and more steriods and then ended up with peri oral dermatitis which at that point I felt so low and frustrated. They eventually referred me to a dermatologist. This had taken 8 years. I stopped all steriods which stopped the horrid spots all over my chin and nose and when I mean horrid it was horrendous. I decided to stop steriods completely. Which was great as my face cleared up. My appointment came and I had just come back from spain but when I got back... all my scalp had cleared and so had my bottom (it was a miracle) however I was due my first app and I had nothing to show (typical). Although it did come back a few weeks later! After a few appointments and different treatments nothing had worked. My dermatologist was surprised and asked for a second opinion. The lady consultant had a look and she said straight away that it was all related and I definitely have psoriasis in both places.. So here I am 9 years later wondering what lies ahead. The above subject is what I have been diagnosed with bottom wise. I am scared to take medication incase I started with dermatitis again. Has anyone got the same condition that can help me deal with this or has some knowledge about my diagnosis? Thanks for reading my story and I am sorry for the long essey which is 9 years worth lol.