Love derives from two sources, biology and or psychology and operates just like as magnetism or gravity. The biological variety comes directly from dna acting thought hormones for the purposes of reproduction. The psychology variety (which also comes from dna) but acts though neurons for the purpose of preservation.

Both are valid forms and both essential to humans.

You will fall in love with a mate that is a suitable match with your evolved personality profile.(i.e. girlfriend boyfriend) for the purpose of reproduction. You will also fall in love with anything (not limited to just people) that generates extreme emotional comfort [mum, dad, special places, special outcomes (i.e. money even)]

Biological loves wains in step with your reproductive drive. Psychological love on the other hand can wax or wain depending of the strength of the external source in producing emotional comfort within us. (i.e. the more your pet provides you with pleasurable emotional experience the more you will grow to love your pet or anything or anyone else for that matter)

The only important thing to remember about psychological love is that WE determine the way we feel NOT others [that is why some people can still love their children or their parent no matter how badly they get treated by them because just like magnetism we at the emotional interface reverse the polarity of the negative into positive- to protect ourselves from negative out come (e.g. my mother/child does not love me = emotional hurt. Therefore we can reverse this to ‘they do love me they just don’t show it = I am loved by someone important to me = I am okay = emotional comfort)

So you can grow or let die or kill even, Psychological love when ever you want to but the news about the Biological love is not so good.

Well there you have it not such a big mystery- really

For most of my life, I completely believed in the notion of romantic love, and magic. I devoted the last thirty years giving a man every thing I had. I walked through hell for him. He has only grown colder and colder through the years until now, even though we share the same house and a beautiful son we both love so much, we barely speak. I realize now my vision of who I thought he was, and who he seemed to be the first years of the marriage, was not who he actually was. I am disillusioned, desolate, destroyed. There is no such thing as romantic love, only naïve illusion, and dreams fostered by the incessant lying media. Flaubert warned us in his book Madame Bovary. There's no "there" there. We ultimately have only ourselves, and that's it, folks.

parasvati, would you like to ask your own question and see if we can come up with advice to help you better your situation?

It exists.

The hardest part to realize and deal with is that for some it does not last.

When you realize that the best thing you have ever felt is fading and will not last forever , it does seem that your world collapses with no hope of repair , and for some that too is true , may God help us through these times, but it can happen once , fail, and happen again and be even better than the first.
I have not experienced it, but have been witness to it more than once.
And still believe that the old saying is true , despite the pain and devastation , it's better to have experienced it and lost it than to never have felt that way at all.

Never give up , and never quit hoping . That is when you are truly lost.