This is your illness lying to you.
Truly, it is.
I feel similarly in that I really have no one to confide in. My best friend is bipolar, but she's 1600 miles away and while we can and do support one another, I wish she was here so we could TALK. My partner is wonderful, but I don't think he gets it (but it's not for lack of trying--it's for lack of being bipolar and not his fault), you know? He's compassionate, kind, giving, and supportive in every way possible and I could not ask for a better companion, but I just wish there was someone I could confide in and talk to who really knew what this experience is like.
Regardless, this is not about me. It's about you. And you are wrong that you don't matter to anybody. I know about a whole 3 people in the world and when I get depressed I feel much like the way you wrote that you feel. But this is the disease speaking. It's depression trying to punch you in the face. Don't let it. Punch it back.
The world has changed a lot since the internet came along. Despite our anonymity here on this forum, perhaps
because of that anonymity we share very honestly and deeply with one another. And while it's a different version of friendship, it is friendship. I know that I, for one, always look forward to your posts. I think your perspectives are enlightening, interesting, and add so much.
I think too that the impact of having lost your father and your brother probably makes the sense of isolation and loneliness worse. Even the feeling of having no personal worth. But while you may feel isolated and lonely, this is partly situational and partly the bipolar demon. But what you are NOT is worthless or a waste of oxygen or space, and you do matter to people. And unless you are psychic (if you are, please play the lottery for me and share!! With me, that is) you cannot possibly know that you will never matter to anyone again. Somehow I doubt that you don't matter to anyone now. Maybe people online don't "count" per se, but we care. And we are here!!
Please try to remember that when you are down or anxious or having an episode of any sort or even in between episodes (which can be really difficult for me, so maybe it is for others too) these thoughts are there as part of the illness and their purpose is to tear you down.
I just got through two days of terrible deathly somewhat probably psychotic depression and I had these thoughts and many more...but I woke up today and the switch had flipped. And it will flip again. And again. And again. My point is--your switch will flip too and when it does you will hopefully see that you have light inside you, that you DO matter, and that you are important in the world...whether you see it all the time or not.
I hope you feel better soon. I know maybe online is not the same as a person you can sit with and sip tea and confide in, but it's something and you are very much a part of this particular place and it would be noticed if you suddenly weren't here. And you'd be missed. I think that means you matter to somebody(s).
You are not insignificant.
I'm getting a new tattoo this week. It will say: My illness lies to me. When I realized this a few weeks ago and started repeating it to myself I started to believe it....and for good reason--it's TRUE.
You are not insignificant. You are bipolar. There's a huge difference. Please try to see some light somewhere in this and see the difference. You matter.