While I realize that it is an entirely personal matter, I can't help but ask if you can perhaps share some of your insights?
A major reason for my depressions where my fathers early death, which i hadn't really processed up to that point. In my first ever trip, some hours in i fell into a state where all that sadness and regret just overpowered my conscience, quite literally myself. Yet at the same time i was calmly observing myself, and i was able to reflect quite deeply onto my emotional state, ironically all whilst beeing utterly unable to control it.
This "loss of ego", i could maybe describe it as an "out of body experience" made it incredibly obvious to me how to put my regular emotional state into context and understanding how rejecting the process of grief and feeding my fears of loss had created the state i was living in.
Afterwards all those things that had an unshakeable grip on me started to become understandable in a way you'd understand ANOTHER person going through this, reasoning wasn't clouded anymore from my affection. I think that was the tipping point
As an example: given that you have free will, at any moment you could say to yourself, "hey, there are X and Y habits/traits I have, let's not do those anymore and do Z instead." Maybe it's smoking, eating badly, you don't treat people the way they deserve, being a doormat, whatever. You could absolutely choose to become an entirely different person overnight. You might also change your career/lifestyle overnight (not everyone is so lucky though).
Now the ego swoops in and says, "Hold on, let's not do anything crazy, it'll be scary and embarrassing if I suddenly act differently, what will my friends think? It's easier to keep on keeping on. These habits are just things that I would do. It's okay when I do these things because I'm me." and so on like this.
It's helpful to be able to experience the world without the influence of the ego, because then you are able to experience the world in a completely unfiltered way. You are able to get closer to an experience of objective truth.
Many people who have used psychedelics or work deeply with meditation all come to similar conclusions: the ego is an illusion. All beings are one and the same. Your sense of "separateness" from every living thing on this planet is a function of your ego-filter — and your ego-filter is wrong.
It's strikingly similar to death experiences I've had slowly waking up as I die in morning dreams ...