Welcome back again

and well done on making the first move of introducing yourself
I think first you need to make a realistic plan on how you are going to lose the weight. I always found that setting myself to lose 2lbs a week or more was unrealistic, I never hit it!! So I planned on losing 1lb a week (I started at 323lbs

) Losing slowly like that meant that I was teaching myself about food and nutrition along the way. I didn't want to gain it back, so I had to make sure that I was equipt with enough knowledge to be able to handle the maintenance. The app My Fitness Pal, helped me first of all to see just what was in the foods I ate. Then I would swap foods for healthier version with less carbs and more protein. It was also pretty good on guessing the amount of calories I burned doing certain workouts, even housework! This was good for me especially when I didn't have a sports watch of any sort (that will change this xmas though

). I maintained for the last 6 weeks of university, and after travelling a lot this year, I haven't properly caught back up on it, but I have lost 39lbs through diet alone.
So hopefully these tips will get you started
1) learn about what you are eating, then change accordingly.
2) Add in exercise, that can be a 10 min walk everyday, just do anything more than what you do just now.
3) TELL EVERYBODY!!! When people know that you are losing weight, you hold yourself accountable to actually produce results. Show people through photos on social media that you are out exercising or eating a healthy meal, tell your friends and family that you cannot eat a large piece of pie because you are watching what you are eating.