Personally, eating extremely clean helped me shave off ~20 lbs in about a months time. I ate three times a day and worked out by running at a local track five days a week with some pilates exercises every now and then.
My advice to you is to remain motivated and constantly fill up on water or any type of tea you enjoy (black, nothing added) and chew sugarless gum when you're first starting off whatever diet you choose to do. A change in diet will obviously result in some hunger pangs that will feel uncomfortable and might cause you to indulge in bad foods or maybe overeat.
Also, it seems like you are very reluctant about exercising so it's probably best to work out when you're feeling your best and remember to associate positive feelings into your workout. Think about how good your wedding photos will look or how pleased your family will be to see you nice and healthy on your special day -- whatever sticks. Fixing up a good playlist helps get your energy going too and keeps you a little distracted from your workout which helps when you're getting tired.
A common thing I hear about weight loss is that it's 70% diet, and 30% exercise so try to avoid splurging on your episodes of white bread and such. After all, you don't want to ruin any efforts going in. Seven months is a long time and I've heard/seen great progress and success stories so all should be well if you really do commit. I believe you can most definitely get down to 150 lbs if you tried.
(Side note:
http://www.myfitnesspal.com and
http://www.loseit.com are both reputable sites for keeping track of cal in/cal out and generally have a nice, supporting community. The food journals come with custom plans that can be adjusted to your liking and are so, very helpful. Check the sites oout)
Lastly, please please please pleeeeeease do not fast. I've done so for only about 4 days and it sucked. Your jaw begins to ache, smell is enhanced, requires a lot of focus and you're extremely weak all the time. I did lose like 10 pounds quickly but of course, it all came back plus more; it is absolutely not worth it and it is depressing. Being able to achieve something by planning and attaining goals in a reliable way is much more rewarding in the end and you'll probably learn so much about your body that you did not know before. Additionally, your willpower and mental state of mind will also strengthen significantly.
Good luck to your future!