New treatments with short term results

I first developed psoriasis when I was 7, I’m now 25. I have widespread aggressive psoriasis (my doctors words) which covers my body head to toe in small patches, (not sure if there’s a medical term for the spread) I’ve found that tropical treatments work extremely well for the first few weeks/month of using and then the psoriasis comes back worse and more aggressive then it was before. Each time I try a new cream/ointment the relief is short lived. I have had 3 course of UV treatment, each more successful then the last in that it resulted in me being psoriasis free for a time. But each time I had the treatment the psoriasis came back worse and more aggressive then before. I know it’s not curable but my doctors/dermatologists seem stumped because of how quickly and how aggressively it comes back each time. Every time I try something new it gets worse after a month or so, it’s as if my body is fighting against the new treatment. I’ve now been referred for a new oral treatment which my GP didnt know much about but my appointment isn’t until October. I just wondered if anyone else has experienced this kind of wide spread and aggressive psoriasis and if they have any advice as my doctors seem to be at a loose end, hence the referral (finally) trust me I have tried every tropical treatment that can be prescribed and many that can’t! On the plus side, I very rarely get ill with colds/flu etc. So the over active immune system must be doing something right! Interested to see your replies Thanks :)