Where can I be in 5 weeks?

So I keep getting loosing weight, then putting it all back on ect.
But I am going to Hawaii in 5 weeks with my boyfriend.
I am currently 61kg, and i am 5ft 4.
How much of a change can I expect to see, and how can I get there?

I am ready to do anything, I have recently gotten back into exercising, I am going to Zumba twice a week and Body blast twice also. But I am also trying to start running.
I am unsure on if 1200 calories is the way to go, eating back exercise calories and everything.
Any advice would be lovely :)