You've actually just had multiple people turn up and tell you how much they care and give you some solidly good, genuine advice, and the only one you bother responding to is the single uncaring joking comment?
Maybe you're choosing the wrong things to focus on and the wrong people to be around in real life, just like you just did in this thread.
You want logical approaches? There are only three possible true scenarios here:
A) You really are treated like this, and it's because you're an asshole.
B) You really are treated like this, and it's because literally every single one of the tens of people you know well enough to care about are assholes.
C) You aren't really treated that badly in general, your perception is just skewed because of your current unhappiness.
(D) You're a troll is a fourth possibility, but assuming otherwise.)
In terms of likelihood, C > A > B. It's statistically very unlikely that B is true - that everyone you know is terrible, shitty, abusive and uncaring towards you. Very very few people are like that, especially to those they know properly, so the chances of it applying to all the people you know is tiny.
However, it can happen, so if it is this (almost definitely not, but hey, shit happens) then try to shift your social circles. You're at uni; it's relatively easy to do, there, just go to a new set of societies/clubs (for example.)
But it's almost guaranteed to be A or C. If it's A, maybe you're unintentionally an asshole, like you've kinda been in this thread, or maybe it's because you're so very self-pitying (we've all been there, it's not an insult), or whatever. Point is, if it's A, I'm not saying you're inherently a bad person, I just mean that you've driven the people who care about you away for some reason. I can't blame them if the way you talk and act in this thread is the way you truly are all the time as opposed to a brief outburst of emotion. If all the people in your life disappear from it, usually you're the cause.
So here is my first tip: Instead of only focusing on everyone else and their flaws, try thinking about yourself, your own happiness, and your own flaws, too. Don't define yourself by your relationships with others, and also don't make yourself so busy criticising and blaming everyone else that you're blind to your own problems.
In this thread you have already been rude and dismissive to others who are trying to care for you, and are utterly focused on how flawless you are and cruel everyone else is. If that's how you are all the time, that's where I'd start working on things.
Or, it could be C) - that the people in your life don't all hate you (some of them might, but that's life, you can't be friends with everyone), and it's simply your unhappiness that's skewing your perception of the world. I'd think very very seriously about whether this is the case, if I were you, because it's definitely the most likely scenario.
I've been where you are. I was clinically diagnosed with depression a year ago almost to the day, was on SSRIs until May, eventually brought myself off them and now I'm back at university. I've got 60-80 hour weeks to deal with for the rest of the year just to keep up with my commitments and still also afford rent. And I've had periods of intense loneliness too. So I'd advise listening, because I have actual practical experience of your situation!
The one thing that has allowed me to somewhat turn my life around is realising that I'm not alone. I was at huge odds with my family too at one point, and I felt like I had no friends. Honestly, it was a combination of utterly not appreciating the help that was offered to me (for example, focusing on one negative comment on a thread instead of several positive ones...), and of driving further help away by lashing out at the people around me, not appreciating them, and being so consumed by my own misery that I became quite self-focused. I was convinced it was me vs. the world, as you put it, that I was good and nobody cared about good people, and I pushed everyone who could have helped away from me.
This is a self-perpetuating cycle. You have to break this cycle in order to function and recover from this. A lot of dealing with common mental illnesses (depression, anxiety, bipolar, and similar) is identifying and eliminating these sorts of negative thought cycles. And although it can feel like you're out of control of your mood when you're mentally ill, you're not. You have the ability to change this, at least, if not your brain chemistry. Everyone is different, but, again, this is from personal experience.
So next time you're feeling like this, stop, slow down, and think. Think about the people in this thread who are very obviously wanting to be a helping hand, who are being kind and compassionate. You are not ignored by everyone, and help is there for those who ask for it and are able to accept it. And then go on to think about other times in the last week when someone has been good, as opposed to just a flat out asshole as you claim everyone is. Identify the positive influences in your life and focus on cultivating them, and show your appreciation for them. Don't obsess over one negative thing in a sea of positivity, and allow that to corrupt your view of the world, as is so easy to do in these times of, well, depression.
I hope this somewhat helps. My final bit of advice is: look at Cognitive Behavioural Therapy sessions with your local health care provider, wherever you are. It's very good, and it's all about breaking negative thought cycles. I used it a bit myself.
Good luck.
