(Oh my ffing god, I wrote a huge-ass post and it was deleted because Trisphee logged me out. ._.)
I hope I remember most of the things...
Anyway, wow. I think it was pretty damn awesome that you realized it, and I dunno, plan to take action. You already know you aren't alone, so I'm just gonna share a bit. The first teenage years of my life was spent in isolation (Actually, and the previous years before it), I had no school, no friends, no social whatnot. So when I began to actively take part in the internets, I had this thing about being needed, that my friends online were the only things that mattered. (Not that this affected my real life, nothing goin' on there)
Then things were pretty harsh, after all the big bad stuff that happened to me, I kind of inched away from people. So kind of the reverse extreme. Except I still had that nagging feeling that I was so alone, and lonely. Which I was, it was pretty damn sad actually. Throughout those years, I just kind of adapted to the feelings, I met new people, I stopped talking to some and I realized one thing, I actually had a handful of people genuinely care for me. I learned my lesson though, I didn't cater to their needs with their beck and call, and the best part is they didn't expect me to.
So, somehow this world blessed me with the three best friends I could ever have. It just happened. I learned to trust people more but I still kept aloof, I learned to love myself (this isn't as bad as it sounds...) to some degree and I kind of just got the hang of balancing out my alone time and stuff.
Sometimes I have this urge to simply do something for myself, whether it's good for my body, it's drawing me something or pigging out of that delicious ice cream bar. (Everything in moderation ;_; ) Maybe you just need a little alone time, something to yourself. Draw a picture that makes you feel all fuzzy and nice inside (mmbloodandgore?), or well, you know. Other things too.
I think you're just in a slump, I think you do care for yourself because you know you have to stop thinking these things. From the things you posted up there, I think you could do it too. I wrote all this because what you wrote there made me really like you (not like that!), it was actually kind of inspiring. And hey, it was in favor to yourself, too!
Besides, taking care of yourself helps everyone around you. It might inspire them, it might just change their lives forever. (A bit exaggerated but it's not impossible.)
I once had a friend who told me that he truly didn't care about himself. And the only thing that did was break my heart. (Not romantically speaking, just, it was sad.) He was such a great guy, with flaws, yes, but he had absolutely no reason to feel like that. (Okay, he did but he had ALL the power to change it).
I'm a firm believer in 'alone time', just little things to yourself, you know? I always draw freebies, and my art is always for someone, whether it's a gift or a surprise. But sometimes I just like to draw something for me that makes me proud. And being proud of myself gives me fuzzy feelings inside.
I care about myself because at least it saves the headache of my friends(kind of ironic here), makes me feel better about myself (god knows, I have serious self esteem issues) and it actually helps me be a bit more likable. XD; I'm not near narcissistic or anything, but I do like myself to some degree(It's a secret though). I learned I didn't need anyone, but life would sure as hell be a lot lamer, duller and sadder without them. But I need to take care of me first, since I wanna be around to bug the crap of all the people around me. ...I just learned to be a bad ass, really. *Cough* *Shot*
I don't know if this will help you or is just some long-ass post that rambled about stuff, but... hey, I hope things get better. Really. And you totally have to give yourself a little love. Remember those goals and remember how awesome they're gonna be when you reach it- but the best part is mostly the journey. So remember how the hell you got to finish the goals! So don't feel so glum, I'm sure you're a lot better than that.
(Hnng omg it's still so long. It's okay if you don't read it.)

Long, long hiatus.