Honestly, what is even the point of love/loving someone?

After four very toxic relationships (from someone breadcrumbing me, to one controlling me, to another one cheating, to one wanting me to become someone else entirely). I thought I was finally in the RIGHT one. He cherished me for how I was, wanted communication, was honest, and was lovely. It took some time to go past my trust issues, but then I was 100% in.

I was in a relationship I truly was happy with, I worked on the issues he mentioned, I invested myself happily, I put effort happily, I "did everything right" , as I accepted his limits and loved him UNCONDITIONALLY.

And what is the reward? 3 years later, I got "My feelings for you changed, I have affection, not love anymore".

I was happily in love, and he was thinking this stuff for months. FEELINGS CHANGE. So what is the sense? Yes, there might be good people outside but NOTHING, NOTHING assures me that the next person will not look at me X years down the line to tell me his feelings changed, even if nothing in our dynamic changed or there was no fight. I am four months into this hell I call reality, where I was punished for making him happy?? (his words after BU have been only positive?? WTF)).

So. To those that do have hope ....what is the sense of love? it seems a stupid construct that does not last, even if you do everything right. And I refuse to be in a relationship where I am used/abused again or unsatisfied, as I see so many of my friends fighting but sticking together because they fear being alone