I am falling in love with you translates as Ich verliebe mich in Dich or Ich bin dabei mich in Dich zu verlieben.
ich verliebe mich in Sie
Falling for you, i would say, is a way of saying "I'm falling in love with you". It also seems to carry the connotation that one is falling, uncontrollably, into love. It indicates the act of the 'fall' into a state of love for somebody.
Will you love in German is wirst Du lieben
But do you love me is aber liebst Du mich? in German.
You can say "আমি তোমায় প্রেম করছি" (Ami tomay preme korchhi) in Bengali, which translates to "I am falling in love with you".
Love one another as yourself!
English: "I am in love" is German: "Ich bin verliebt".
I'm falling for you = Ich bin dabei, mich in Dich zu verlieben.
I can't believe I am falling in love with you
This is a metaphor for falling in love.
Liebe
Well they do say liebe = love