Agreed, good write up and reminds me a lot of my most intense ego death also on mushrooms. Only in my case I did not choose to nor did I know it was even possible, but being in hell so badly that I accepted possibly dying or going insane over continuing to struggle I surrendered and slipped into it, it lasted for about 5 hours and yeah it involved something similar, like a white dot in blackness. Very abstract, also partially a paradox since there were themes of non-duality and it was not as clear-cut as a division between that white and black... rather it wasn't black like empty space but VOID!
Another paradox that has involved many extreme OOBE / mystical states I have since been in is that in order to gain ultimate power (pertaining your own mind and being) you have to let go of everything including desires... desire for that power, desire to live even ultimately. This makes some things almost impossible to force, they would need to happen by accident just from trying shit. And to add to some clichés here it is resounding in the lyrics 'you cant always get what you want but if you try sometimes you might find you get what you need'.
If you want to get a more stable and therapeutic in this same sort of theme I highly recommend picking up Zen meditation. Unless you are as driven and disciplined as you were insistent on this ego death trip, you will want to do it in a group with others to make sure that you don't give up. Actually similar things happen only it is much more down to earth: just sitting you struggle with yourself and your position and certain paradoxes like having to 'not want' or 'not desire', not even the emptiness in your mind which is a classic beginner mistake regarding meditation.
Psychedelic trips are incredibly comparable to meditation. Only there is a big difference in how psychedelics forcibly induce things and with meditation things happen naturally and at a more reasonable pace.
You can change by just willing it, but that Leary quote is very optimistic as change tends to take time. Start by having compassion for yourself and your flaws, and patience. There is nothing wrong with using the time in your life you gradually overcome flaws. If you do not accept yourself first as a starting point, you are bound to struggle pointlessly and waste time and energy. I have discovered wanting to enhance yourself, become a better person very fast or change irrevocably... it can be very hard to have an overview of what you are doing and you should be very careful what you ask for as there is really no guarantee at all that things are getting any better or easier. Most psychedelics and nootropics did though, is to cause me to become an even more pronounced me - positives and negatives. This gives opportunity to work on yourself, but also makes it all the more confusing and very heavy / hard.
And a warning: when I went through quests like these they raised so many more questions than answers that I felt like I had to excavate my entire being in other to resolve things. If I weren't lucky with certain things I might not have made it.
Take it easy and try to have some confidence that if you work on yourself within reason, surprisingly you can get ahead much more. This seems like a paradox, and it is one of several like the 'ultimate power' one that I have come across that are among the biggest revelations in my life. I went at this the hard way and I truly hope you find the wisdom to take an easier one, even though they feel like they are opposite.