Hi Elizad
welcome to Social Slimmers
Why not try to make a food diary and write down everything you eat each day to see if you can spot any patterns of food that you are eating that you may not notice? I know you said you haven't changed anything significant in your diet, but small changes can make a difference that you don't realise.
I would say that rather than losing the weight quickly, you might be better to lose the weight slowly (1-2lb a week) as it would be easier to keep the weight off in the long term.
If you dropped the weight really quickly and suddenly, I would imagine it would be more likely that you would put it back on quickly too.
I always put on weight over Christmas, but I've put on less this year than I have in previous years due to smarter eating (more fruit & veg rather than the cakes & biscuits
lol)