I don't think he's self destructive at all. Or better, I guess he has no idea what 'self-detsruive' really means. He seems to take very good care of his appearance, life and overall health, actually (except for the spine issues, but hey, that's a hopeless cause). I mean, look at him: very nice teeth, very nice skin, probably gets botox monthly, probably eats right and works out (otherwise he wouldn't be in such good shape), sounds like he's followed by doctors regularly, etc. For us shrinks, a self-destructive individual is your next-door hobo who hasn't been to the doctor or dentist in ten years, doesn't shower much, lives off instant noodles and pizza, smokes five packs a day and starts drinking at noon. Even more intentionally self-destructive behaviour is self-harming, provoking overdoses for the sake of feeling like crap, anorexia, bulimia, intentionally quitting your job and dropping out of your social circle because you don't think you deserve those, etc. Compared to these, insisting that you want to drum despite your limitations and making a big deal when you're seriously tired is not much, really.
Yoshiki, bro, you're actually doing 98% better than most humans, word. 
I agree that he might not have self-destructive issues nowadays, but back in the day I'm pretty sure he was self-destructive maybe Hide as well (cuz his alcolholism). He lost his father when he was 10, then he became suicidal ever since and that resulted in his mother indulging him, believe me it's rare even in Asian culture (I mean giving him that amount of money to debut). I believe his mother was feeling so sorry for his little boy going thru such tremendous pain at that young age.
IMO, he was always hurting himself to achieve his "aesthetics of destruction", it's actually an aesthetics of Japanese culture, if you read Japanese books, especially the ones written by Yukio Mishima who ended up committing suicide after finishing his last book, you will understand what I'm talking about, this "arthritics of destruction" represents extremism in Japanese culture, which is not uncommon.
When he lost his father, he was in great pain and all his life after that he keeps having PTSD of that particular day when his father committed suicide. His way of venting is rock and drum and hurting himself. He said he was into only classic music and piano before his father died, playing drums is his way of let out his hidden emotions and pain out. And that he believes he would literally die when he's 33 or 34, around the age of his father's death. So he was really hurting himself intentionally and trying to achieve the peak of his "aesthetic od destruction" by being dead at the age of 33 thru whatever he could possibly do, like playing drums in a irregular way, drinking, having mental issues, putting too much energy to work and so on.
Everything changed after HIDE died, Hide was playing a role of mother in X Japan, he took care of Yoshiki and intended to reunite X Japan w him after 2000. He was Yoshiki's soulmate and Yoshiki relied on him so much. When HIDE died, it was a whole another level of pain, no less than his father. I personally think Yoshiki's biggest pain is the death of his father, where all his pain started, and HIDE'S death, which took his pain to another level. He silenced himself for two years and time went on, he's changed. He's over 55 now, not as self-destructive as before, he tries to cherish life and continues Hide's life in another form. That's why he's maintaining his skin, teeth and body, trying to perfect his image as a public figure, or maybe he simply just wants to be as beautiful as he was. But judging from his interview, deep down his heart, he still wants to try his best to work, life left him nothing but pain and music. He's a poor man indeed. I know he has a lot of people taking care of his life and his fans worshipping him, but nothing takes away his pain. Perhaps he likes to be in the center of spotlight or whatever, but there's one thing I can guarantee you, is that he's constantly in pain, he never forgets his father and HIDE's death. He keeps thinking about their deaths and memories he had with them on his head, that's why he keeps mentioning HIDE in his interviews and the way he says the things happened between him and Hide is so casual, like it happened yesterday, like HIDE is not dead. He must recall these memories for thousands of times so it was like it happened not so long ago.
Now he chooses to speak up about his pain for whatever reason (he said it's for encouraging others who's in pain to bring them strength), as a celebrity, he's so brave.
Guys, losing father at such young age and keeping it as a secret for decades, losing life long soulmate, disbanding X Japan and losing his childhood friend (who's now back), these things are not fake, I don't think he's convincing himself to pretend he's in pain to put on a show in stage or his life.
