But you have changed me, your elegance, wit and beauty have smitten me AND opened my eyes to another side of love.

All I know now is that a week without seeing you feelS like an eternity to me, and the thought of not having you around tears me up inside.

Though I can’t promise endless days of rainbows and flowers, I believe one must take chances when presented with an opportunity TO LIVE something wonderful.

So by your permission I would like TO TAKE the chance to get to know you better, ASK you out on a date, take a step further THAN friendship and see where fate leads us.

>any fancy alternative for single life? i consider bachelorhood but it's not exactly the same meaning

you could replace "single life" with "living on your own", "unattached life", "celibate life", "companionless life". But single life seems actually pretty good.

>is it allright to use love or is it too strong? (last sentence of first paragraph)

Love is fine. You are writing a love letter, after all. And it does not mean you want to marry her.

>how stupid is the secret admirer thing?

I also think it's fine and appropriate