> How did you handle meaning after that?

Meaning is real and very important but so is the craving for it and it's a good thing.

Like the craving for love/object of love?

I've had dreams in my teenage years about an ex loving me back and I can still remember how happy I was and a bit hurt when I woke up.

The deep realisations, euphoria and profound happiness -- these are not something the human brain can experience every day, it's in the very nature of the brain's chemistry to downregulate if you feel them too often.

Another example -- the first time I took isopropylphenidate, I was staring at this ancient PLSQL stored procedure bug and I realized SqlDevelop had the option to debug the code just like I could debug my java code. My colleagues were basically pulling at me to go to lunch but I was enthralled by how beautiful the SqlDebugger looked and felt, even in UX terms.

The same about my 1 years old daughter obsessive playing with water and children's excitement when they discover mundane(to us adults) things. To us adults they seem to be on MDMA, but it's just the nature of the brain to be so excited about new experiences that it deems "profound" because it's the only way they can learn about the world -- you have to be motivated to exercise those neural circuitry to learn about the word, otherwise you become catatonic .

Also take for example this experience I had playing Catan board game with my wife and brother in law. It had profound meaning to me :). For once, I discovered how much satisfaction a few pieces of cardboard and plastic can bring to humans.
My wife and her brother were highly competitive and I played the broker between them. I would always accept their trade offers. They thought they got the better deal, but just because they gave me 2x of the stuff they didn't want I was far ahead of them in the game. Because they did not want to trade between themselves and only traded with me, it mean I would get 4x the items they could have traded directly between themselves.
I would win the game and not tell them, I would just watch them compete and play along with an inner smile. I'm sure life is like this for some people, who have won at the game of life but others just don't realize it.
But the very fact that the game had such deep "meaning" (the feeling) to me made me realize the deeper meanings of being together with others, that the human interaction itself has meaning, that money and a lot material possessions are utterly meaningless and we're giving them too much meaning by introducing a lot of negativity in the game of life just to give them meaning, finally that taking life in a light hearted way, helping others (as long as on your terms) and the human ethos are ALWAYS with you (in a Dune "other memory" sort of way) and those are not 0 sum games and can bring a lot of joy into the world.

Anyway, I think that "meaning" is something objectively true and real (controversial, I know), but our feelings and "aha!" is not and it should be taken with a huge grain of salt.

And if it's true for such a beautiful and positive feeling, how much more so for negative feelings?

These experiences made me more flexible, empathetic towards myself and others and more mellow in general to ideas.

A lot of rambling to say that the experience of realizing a deep realization of meaning in a dream/hallucination was utter garbage does not disprove meaning itself, but the contrary, that meaning is something very important and true to humans and we crave it deeply, we just have to find the right places to find true meaning to us, very few people can find true meaning in great mathematical ideas, but ALL of us can find it in the "mundane" and if you find it there you'll find that it won't be garbage the next day you wake up, young or old, 10000 BC or 100.000 AD.