I lost my first 30kg in 12mths, you can do it!
Like going on holidays, first have to decide your doing it!

Suggestions:

NO sugar!!
limit carbs
try "planking" for core (1-2mins to start will have you sweating!)

Save gym fees & buy great fruit & vegetables!

http://www.mensfitness.com/weight-loss/burn-fat-fast/how-to-do-a-plank-a-single-move-for-stronger-abs

Good luck!
Hope that helps.