Lothar has the general idea with the weight loss, avoid the carbs really they stick in your body and cause you to bloat. Pizza, pasta, potatoes, bread and carbonated drinks are the biggest ones to cause problems so go and throw them all out now.
Meats, cheeses and greens are good in any amounts, fruits are good too, bananas, apples and grapes but don't overload on them, lots of sugars in there which can have the opposite effect, 2-3 pieces a day is good.
I know it's easy to say but the sooner you kick those bad things from your diet the less you have to worry about in the future. Last summer I weighed nearly 115kg (18 stone) I cut out all the crap and dropped down to 104kg (16.3 stone) without doing an extra exercise, just changing what I eat.
Drink lots of water, you should be getting back at least 2L a day for someone of your size. Don't drink anything else, stay well away from things like squash and especially beer, fruit juices are ok but the sugars can stack up if you have too much so one or two small glasses a day a most.
As for exercise, get out there and walk, put some good shoes and headphones on and some music or get someone to come with you and talk to them, the time will fly by, then do it again tomorrow, go explore around where you live, find a random path and see where it leads.
Hope you have a great holiday when it comes round!!