It sounds like you have a lot of weight to lose. Believe me, you CAN do it. There are so many people on here that have lost a ton of weight. It's going to take some time, but you have got to know that it is achievable. I recommend starting with the nutrition/food tracker because that's the key element in weight loss for most people. Yes, it takes some time, but the results are soooo worth it! I lost 90 lbs and there's no doubt that the food tracker was essential for me. Once you are comfortable with tracking your food on a daily basis, you can start exploring more areas of this site. I still find something new here almost every day.
Also, it's super important to set small, achievable goals. These small achievements will start to pile up, and one after another, you'll start feeling a natural momentum and motivation that can carry you through to whatever goal you want to reach.