Sleep is my worst enemy!

Hi all, I'm 23 and have had varying levels of p my whole life. Up until about 19 I had nothing more than the occasional blotch on my elbow or inside of the knee. Since then my condition has been like a rollercoaster from hell. Most recently I've been on methotrexate for about 16 weeks but to no avail. Also had uvb treatment but after over 20 sessions there was still no improvement. Right now it's about as bad as it has ever been. Have blotches and red patches all over my body including hands and feet for the first time in my life and the situation on my scalp has never been worse. I have classic dry scalp with patches on the top of my head which is annoying but manageable. Where it is significantly worse are the back and sides of my head. The sides of my scalp are about 80% covered in yellow crust and the back of my head had plenty of them too. This happened in the past and a week's worth of flucloxacillin dealt with this quickly however this time around I had 2 weeks of it and it did nothing. It is mortifying waking up each morning and seeing the amount of yellow/clear liquid which has weeped out of my scalp and onto my pillow cases. I know people say don't scratch it but the issue is that the vast majority of my scratching happens whilst I'm asleep. I wake up and realise I've been itching the crust and the rest of my body but that's out of my hands. I've tried tgel for my scalp but that's really not made a difference and I've even tried knocking myself out with melatonin to stop myself itching when sleeping but that's not made a difference either. I'm just so fed up of this situation and instead of looking forward to a good night's sleep I genuinely dread it as I don't know how bad my skin will be when I wake up. I've tried all sorts of antihistamines whether over counter like cetirizine or fexafenodine but to no avail. If anyone has any advice that may help then it would be greatly appreciated.