Hi, Glenda. I live in Houston and just had my surgery on Jan 7. I haven't gotten to weigh yet. I was 310 on Dec 31. I too have lung problems and I use oxygen. I have been doing my 30 min a day walking though as I had to sign a contract with my surgeon that I would do that.
I think it is normal to plateau. Your body is just catching up. If you are drinking you fluids, walking and taking your vitamins, it will come off. Just hang in there. Hopefully, your breathing and mine will get better with the weight loss. God Bless.