First of all..... Well Done for taking the plunge and stepping on the scales. I weighed in at 323 in January at my heaviest and I felt different at that point as well. I realised that I just has no motivation at all......walking to the shop (which is just 6 or 7 minutes away) felt like walking the grand canyon. My clothes looked different on me, I walked slouched and I was getting odd back pain.
I decided to go back on the My Fitness Pal app to register what I was eating. I set my calorie goal to 1500 calories and within the first week I lost about 7 lbs of water weight or something, whatever it was, that first part was the easiest. I joined back up at the gym (curves) and did a 30 minute circuit twice a week, then built it up to 3 times a week with one 30min circuit staying onto a 30 minute Zumba class. Stress from my last few months of uni was stopping me loosing weight no matter what I ate. But now I am 26.4lbs down as of this morning, and if I didn't have my fitness pal app I have no idea what I would do.
Now I am down to 1350 calories a day, and I try and walk 5,000 steps 5 days a week, and 12,000 steps twice a week. I cant do the gym any more because of some bad arm injuries.
But I think you will do well
Just take little steps and aim for 1 or 1.5 lbs a week loss. Slow and steady wins the race....