Welcome! I hope you find all the support you need in here. Our stories are similar except I'm 10 years older than you. I wasn't heavy as a child or young adult, but when it started piling on in my mid 30s, there was no stopping it.
I got tons and tons of encouragement last year when I was losing. Just keep at it and the pounds will start to come off again. I wish I had measured from the very start. It was hard enough to realize I weighed over 250 pounds. I didn't think I could handle the measurements. Now I wish I had. My only reference was a pair of slacks that fit like a second skin at my heaviest. I measured the waist and hips of the pants before I gave them away, so that's the best estimate I have of those 2 measurements.
I went from a 24 to a 12 last year. Stalls happened, though not too often. I just kept the memory of how big those old pants were in my head and that helped me stay on plan. I just reduced cards, sugars, and fats, and stayed under about 1500 calories. No set plan like WW or Dukan. An acquaintance at work did Dukan last year with great results. I hope it continues to go well for you.
Life style change started on Jan 13, 2011. I was going to lose 100 pounds by Christmas.
I lost 93 pounds by Oct 1, 2011 and am holding there for now. We'll see what happens.
New goal: To maintain at about 160
Final Goal: To decide if I need to lose more
Just Keep On Keepin' On