I agree with the other wise old* men here who have survived the hellish single-lonely-obsessive phase of life.
I don't know how else to help you other than to try and convince you that what you think you want so badly is not really what you would want if you knew everything about the situation and how it would play out if you actually did get what you want.
Like others, I wasted so much mental and emotional energy in my younger years thinking about this crush or that crush. My (now) wife was the first girl I ever dated, but before that it was one stupid crush after another. I understand your mental anguish and in years past was guilty of sappy Facebook posts bemoaning my lonely state... posts which screamed emotional weakness and probably turned off any female reading and would make me want to vomit if I went back and re-read it now (thank god I don't have Facebook anymore...actually thanks to my wife

)
I have sometimes wondered: if I have a son, how do I keep him from going through what I went through? My Dad apparently went through the same thing in his single years and tried to warn me, but of course I didn't or couldn't listen.
I really think you need to hypnotize or de-hypnotize yourself to get rid of this false mental picture you have of what life will be like with this or that girl and train your mind to see that what this or that girl represents is: a lot of pain, heartache, growth opportunities, work, and... if you both have the integrity to stick with it: joy, friendship, and partnership. It's more like climbing Mt Everest than a vacation on a sunny beach or flower-filled meadow: it might be worth it but you also might get frost-bit. Your circumstances will always carry an element of disappointment, but happiness comes from the inside, and what you need on the inside is emotional stability and an optimistic conquering mindset.
Like you, I also had a savior complex wanting to rescue those from bad situations. But don't mistake pity for true love.
It sounds like this girl developed an emotional connection with you while married and that is not a wise move on her part. I know you don't want to ascribe any fault to the goddess, but it looks to me like a serious fault.
Why are women attracted to jerks while nice guys lose? Women are attracted (at least initially) to men who are more successful at climbing hierarchies. Men compete and those who rise to the top are more likely to be stronger physically mentally and emotionally, but the winners are also more likely to be jerks. Nice compassionate guys are more carried away by emotions and fantasy and that is scary for a woman and makes her feel uneasy. So they choose someone solid and then complain he isn't emotional enough. Men and women both seem to have one set of qualities they initially desire which flip to the opposite after the relationship gets serious.
I wouldn't attribute anything metaphysical to this attraction. Not that some metaphysical connection is impossible, but that you are not in an objective enough state to evaluate that. In my church days I heard so many young men say that they thought God had told them to marry this girl or that girl... some girls had 10 or more guys tell them the same thing... lol
I wouldn't be so quick to discount the wisdom traditions. Sure there are many charlatans, but they are attracted like flies to something sweet. The Wu Wei principle would be a big help here.
And your mind needs discipline to control the fantasies and emotions. Discipline comes through various externalities (work, sports practice, music practice) and through internal practice (meditation, forming good habits). Basically discipline builds a stronger mental structure that doesn't melt down to shit whenever stress or problems or longings present themselves.
If you make yourself emotionally strong, you have a far better chance of finding a mate that will bring long term joy into your life. If you remain in an emotional tempest, you'll bring more storms into your life.
Good luck!
