Lots of us get that feeling of despiration at some point. Here's a good way to start: Log your "normal" eating habits for a week or two w/o changing anything. Then use the report features to take a close look at what's going wrong. Many quickly discover that they are eating too many carbohydrates (sugars & white flour found in most snack foods). And we are almost alway shocked at the total amount of calories we are consuming even when we think we are being carefull.
Once you have this information, start modifying your weak spots. I suggest tackling one problem at a time rather than trying to change everything all at once. Too may sodas? Start cutting back. Portion sizes just too big or going back for 2nds? start with smaller portions and knocking out the seconds.
And jump on into there forums. There is lots of wisdom and shared experiences. We are all in this together.