Going with the flow...

Not a day goes by that I don't ask other people or at the very least wonder about how to handle my curent situation. Often the current situation needs only some advice on what to wear or what to cook, now something more serious has come up and it is not at all clear to me what the obvious bad choice is between:

a) Go with the flow, just let it all happen and see where I end, realising that there's an 85% chance if will be a short happy period of bliss followed by a possibly long period of misery and heartbreak.

b) Fight for the one I am now certain that I like/love, realising there's an 85% chance of it ending in misery and heartbreak with no period of bliss whatsoever?

You tell me I guess.