You're not the only one who has skin problems--I had clear skin for a while, but for the last two weeks my face has been tight, dry and scaly, with little bumps, and it looks like hell. Last week, it actually hurt.
Since I'm losing weight now, I suspect it's all the Omega-6s that are being released from my fat stores into my bloodstream, causing an immune response. Last week, I increased my Omega-3 intake to balance it out. Today my skin's noticeably better and the discomfort's mostly gone, but it's still not great.
After looking back at some of your previous posts, I can't help but think you've got a chronic inflammatory/autoimmune problem. Can that be solved by diet alone? Maybe, eventually, if you stick it out long enough. But since you're not seeing any changes so far I highly recommend getting tested for food intolerances. You've got NHS; use it. Even if it turns out that the doctors can't do anything to help you, you might come out of it with new information that helps you more effectively help yourself.
As for your depression being completely situational and related solely to your feelings about your skin condition--if that's true all I can tell you is that you need to stop placing so much importance on your skin. Because if that's true, the state of your skin isn't making you depressed; you're making yourself depressed by dwelling on it and defining your value by it. If your depression is truly situational, you have a choice to re-frame that situation in a way that will alleviate, and even eliminate that depression.
Most people have something they really wish they could change about themselves. Maybe they're poor. Maybe they're short. Maybe they wish they had a different skin color, or were of a different, more favored race. Maybe they've got a chronic illness or disability.
Me? I don't like my teeth. They're my worst feature by far, have been for most of my 45 years, and for the time being there's nothing I can do about them. Fixing them would involve tremendous pain and financial expense I don't have the means to deal with right now.
I'm plenty aware of the fact that when I talk to people or smile or open my mouth at all I'm letting the whole world see how ugly my teeth are. I know some people probably form negative judgments about me, based on my teeth. And I'm not going to lie and say they don't make me self-conscious, especially when it comes to dating.
But there's so much more to me than my teeth. I'm not going to hide away and never smile because of them. I'm not going to wallow in self-pity over them. They are what they are, and I'm determined to carry on and lead my life as if they weren't a problem at all (and, other than being ugly, they really aren't a problem). By focusing on my work, my friends, my pets, my hobbies, and all the other stuff that enriches my life and makes me happy, I rarely have the time nor the inclination to fret over my teeth. And since there are people out there who have it so much worse than I do and don't let it stop them, I just can't bring myself to get too hung up on my unfortunate dentition.
Do I have my down moments, when I hate them, feel hopelessly ugly, and am depressed over their appearance? Yeah, I do. But I catch myself when that happens and don't let myself dwell on it. That's the choice I make. Because letting something like the way my teeth look drag me down and keep me down doesn't strike me as any way to live at all. I don't want to get to the end of my life and look back in regret at all the things I wish I'd done, or the people I wish I'd dared to talk to, but didn't because of my teeth.