I'm so glad you came here to vent how you're feeling. Any dis-ease, unease or deep upset, is much better out than in (holding it entirely within). Your sorrow sounds so overwhelming, my heart goes out to you. By the way, if there's one thing I believe we should be allowed to do, it's to feel sorrow for our self at times. Anyone who says to us 'Stop feeling sorry for yourself', is mismanaging our sorrow and how we feel it.
As Mum to a 19yo gal and 16yo guy, I manage mental health differently to a lot of other parents, based on having experienced depression for a decade and a half earlier on in my life. Mental health is big in our house. As I say to my kids in ways 'I wish someone had raised me to understand that life can be deeply depressing at times and if you're sensitive enough to feel your challenges, you may also feel depression. How to feel and manage your way through depression or depressing challenges is important'. So, there's no suppressing our feelings, it's more so about openly discussing them in order to make sense of them and how they've come about. From what's soulfully depressing (sometimes losing a sense of self), what's chemically depressing (such as a lack of dopamine reconditioning us in some way through all these lockdowns we've had in Melbourne) through to what's mentally depressing (internal dialogue there seems no escape from) it's all relevant to how we're feeling life.
I imagine you can relate to internal dialogue being mind altering depressing. With that old scenario of 'angel on one shoulder, devil on the other', sometimes you can feel like screaming 'Where in hell is the angel?', as it can seem so one sided. It can definitely feel like hell on earth when you also have all these questions but no answers. I think it's the lack of answers which makes it so hellish. 'Why do I tick this way? Why do I feel so much, so deeply? Why am I so sensitive? Where the heck is this internal compass people speak of, regarding a sense of direction? Why can't I envision the difference I need? Why do no antidepressants work for me, while they seem to work for others? Why do I feel so broken?' and the list can go on and on, with no answers. I don't think people realise how depressing it can be to have no answers, especially when you've had no answers, revelations or inspiration for years. Years is a long time. The length of time can also be an issue.
Vent as much as you need to. Give yourself the freedom to openly make sense of things.