Falling Cow, it seems to me that you have already started the mental process of losing weight, because it is obviously important enough for you to start a thread about it. 
Here’s my story, thus far:
Last March, I was in a really low place, mentally and physically. I would be exhausted by 2:30 in the afternoon—I mean, ready to lay down and take a nap. I am self-employed, and spend a great deal of time sitting down at my work, so I was certainly not tiring myself out by moving around. Over a decade or so, I had packed on over eighty pounds.
One day, I decided enough was enough, and that I had to do something, anything, to get my energy back. One of the obvious solutions was to lose some weight, watch my nutrition, get exercise and so on…
I had a hard time with the idea of exercise, because how does one get started at exercise while tired all the time? Wearing a pedometer proved to be the answer for me.
I oredered a nice pedometer off of Amazon.com, and patted myself on the back for making a start. When it arrived, I put it on immediately. For a month after that, I did not change my diet at all, but I made sure the pedometer was clipped to my waist every morning, and I concentrated on getting in the habit of periodically checking how many steps I had taken. Turns out I was walking less than 2,000 steps a day at the beginning of my weight loss program! I started adding a little more walking around each day. At the end of the month, I was approaching the recommended 10,000 steps per day. I did not weigh myself at all until about a month had passed. I was happy to find that I had lost six pounds-- just from wearing the pedometer and being more mindful of how much time I was spending moving around. I also started a new habit of taking multivitamin every morning.
The next month, I replaced all sugar in my diet with Splenda. I have a horrible sweet tooth. I have to have something with chocolate in it everyday, or I become dangerous! I made friends with Blue Bunny Sweet Freedom ice cream bars. I also made a concerted effort to walk more than 10,000 steps per day. I did not make any other drastic changes in my diet; just got rid of the sugar. Before the month was over, I felt more energetic than I had in years. I rapidly lost another ten pounds.
Then, in May, I started keeping track of everything I ate–limiting myself to around 1600 calories a day. It helped me to think of it as a “food budget” instead of a limitation on my eating. I am really good at penny-pinching, and soon learned that if I eat a big salad with lite dressing at lunch, I can have a cheeseburger or some pizza at dinner, by leaving extra calories in my daily “budget” for the splurges. If I avoid the “splurge” foods, I can eat pretty much whenever I want, so I never feel hungry.
I have also learned that the first few bites of a forbidden goodie are the tastiest, so if I want something like french fries, I split an order with someone else, so I get to enjoy the naughty food without going overboard and packing on a lot of extra calories.
After May, I lost patience with writing down all of my food choices for the day, so I only do that every few days, and the rest of the time I try to keep a running tally in my head. This works well for me because my goal was to teach myself to be mindful of what I am eating, and this needs to be a permanent behavior or the weight will come right back.
So far, I have lost 38 pounds. My wieght loss has slowed down a little in the last six weeks or so, but it continues to come off. Interestingly, even though I have not been losing the pounds as fast, I am losing lots of inches right now. In fact, I need to go to buy some jeans in the next size down. In March, my most comfortable pair of pants was a size 22. Now, I need to buy some in size 14. Yay!
I am a bit concerned about how I will do when winter rolls around, since I have Seasonal Affective Disorder, and I tend to run to food when I am depressed. But I think the changes I have made will stand me in good stead, and I am planning ahead for dealing with winter blues–buying more full-spectrum lighting for the house and whatnot. The fact that I now have the energy to get out and walk will help as well.
I do NOT want to end up feeling as bad as I felt last March…ugh. That is a strong motivator for me to keep my new, heathier habits going. Also, when I am in the grocery store and pick up a heavy bag of something–say, a twenty-pound bag of kitty litter, I think to myself that I used to carry around the weight of almost TWO of these bags with every step. I feel so much better now. I want to know what I will feel like when I am no longer overwieght. It is relief to get that weight off, just as it is a relief to set down something heavy that you have been carrying.
I thought it would be really hard to get rid of sugar, but I have found as long as I can get a taste of something sweet, I’m content. As an experiment, I ate a bowl of regular, sugary ice cream (two scoops) about a month ago, and I felt awful for the rest of the day. I don’t miss real sugar anymore.
I have a goal of losing 75-80 pounds. I have not set a date by which the weight has to be off; that would be setting myself up for failure. I am telling myself that it is a permanent lifestyle change, and as a result of the changes I am making, success is inevitable. It is a journey.
God luck to you, and when you are ready to lose weight, you will know it. As others have said here, it is a very personal, individual thing.