Beautiful! I’ve experienced that same oneness and peace. I often tell people that my pronouns are us/we, for all of the reasons that you describe here. Their faces are often confused. I don’t go into detail, just let them sit and ponder it.
Alas that feeling can be fleeting at times. I’m 40 years behind you, yet thankfully in fairly great health. I love and am loved, and that has been one of my mantras since my teenage years. Perhaps it is that love-force that has kept me healthy despite my addictions and depression.
I have to keep reminding myself of the universal-I that I am. Sometimes the universe sends me a message to help kick me back into that state. Today, you and your brother were the vehicle of that message. I wholeheartedly thank you both as I let this tear fall from my eye 🥹