Also sometimes the love can survive beyond the relationship.

Anyway, as far as people's beliefs that if it doesn't last forever then it was never real, I wrote: " love is a state of being — many feel one cannot fall out of true love — here’s the fallacy in that — many correctly believe that we are constantly changing — so, since love is a state of being, it is inconsistent to insist that one cannot fall out of true love. " That's part of this piece: https://medium.com/know-thyself-heal-thyself/unconditional-love-3481bffe22f4

Re Polyamory, here is a piece by Minty Horseradish that I recall reading: https://medium.com/the-phoenix-project/polyamory-an-experiment-for-spiritual-awakening-1111eb457502 and another that I had forgotten that I had read which is very relevant to your developing thoughts on the matter: https://medium.com/monogamish/polyamory-is-my-path-to-self-love-77aafc6b1a3