Welcome to the forum.
You made a couple of duplicate postings which I had to delete because we have a rule that forbids duplicate postings.
While some people do a detox - I cannot say that I have ever done one or believed that it would benefit me... It sounds like a lot of tough and miserable times for no benefit.
I do think that it will help you to cut down or cut out junk food and any takeaways that you may have...
Aiming to drink at least 1 ounce of water for every 2 pounds of your weight will help.
Becoming calorie aware will help which will involve you using an oil spray like fry light for cooking, opting for sauces which are low in calorie, opting for a breakfast cereal which isnt covered in sugar, using things like diet sodas and sweetener instead of sugar, low fat options for dairy - skimmed milk, low fat yoghurt etc...
Become aware of portion size and try to guide yourself towards the recommended portion sizes.
Try to have 5-a-day and have at least 5 portions of fruit or veg across the day... Lots of people do not have enough vegetables and they are great to fill up on and provide us with vitamins to keep us healthy.
Use that gym membership. Lots of people that go to a gym would prefer that they had smaller tummy, thighs etc - but the people that go to the gym are doing something constructive about it... Wear something baggy if you like - tracksuit bottoms are great at covering you up - but the important thing is to go and work hard. I go to a gym for zumba classes - and can honestly say that at my classes - everyone looks wrecked, red and covered in sweat long before the end... When I say everyone - it includes the instructors and visiting fitness instructors and dancers... There is nothing wrong with getting so that you look wrecked - it shows that you have worked hard...
The most important thing is to act immediately and do what you can. In weight loss - it is far too easy to put things off and let things get worse while you are waiting for it to be more manageable or for your to feel up to doing what you think is the best thing. Do what you can today - even if it is maybe cutting out chocolate and going for a 15 minute walk... You can always build on it tomorrow with something more...
I suggest that you read the following thread - it may help you settle in and make friends here
http://weight-loss.fitness.com/threads/57955-My-advice-to-newcomers
Good luck with your project.