Превод - Руски-Английски - чТоо эсЛии тЫ заВтра нЕ поЛюьиш ?! ...

will it be...

Thanks a lot , Lilly.

The construction "Что если"is mostly rendered into English as "What if"

I agree with melissenta, but I would consider to change it all into "What if you don't begin to love tomorrow?". (That is a change in word order and another an addition of the word "begin" except from the change melissenta already proposed)

Excuse my "yes" vote, it was with these exceptions :-) (That is, probably I should have voted "no" )

I thought and I agreed with Piagabriella. I changed my first version.

And I thought a little bit more and I have changed mind a bit. Now I think "What if you won't love tomorrow" would be better (no "begin", but I would keep "tomorrow" in the end of the phrase). I am sorry (if I am a bit confusing...)!!! I think this is my final decision as to how I would have translated it. I had to think about this one for a while.

Piagabriella,
don't worry, take it easy
Btw,as far as I know after "if" "will" and "won't" can't be used. I consulted a dictionary and I found that Russian word "полюбить" may be translated in English like "come to love".

Yes, you are right Guzel.
The possible negative forms for "you" (assuming that the verb to be used is "fall in love" are:
"What if you don't fall in love..."
"What if you didn't fall in love..."
"What if you hadn't fallen in love..."