I'm sorry that you're upset, but there are reasons the psych evals are so necessary. They need to weed out certain people, or in some cases they need to put some requirements on you to help prove to yourself and maybe even the doctor that you can do this.
As has been stated, this is NOT a clean slate. It's a tool to help you. I will be very honest and say what caught me on your second post, and I don't mean it to sound negative or derogatory in any fashion because it's not, but you said it yoruself: You've been seeing a nutritionist for five months and have lost 12 pounds. I'm sorry, but that tells me that maybe it puts up a red flag for the psychiatrist. You will have to do ALL the things you are doing now with the nutritionist, just with a band.
When I have followed a good, healthy-but-strict diet in the past, I was losing about 10 pounds a month. I'm not saying we are all alike or lose alike, but maybe the psychiatrist feels you're not serious enough yet. That you need to put forth some more blood, sweat, and tears before he okays you.
Trust me, there would be nothing much worse than banding somebody who is not ready and potentially sabotages or overeats and injures themselves.
We don't go to the psychiatrists to get rubber stamped for approval. The tests DO weed certain people out. And depression is not the only issue. I suffer from mild depression AND take meds for it. And my doctor knew all about that.
Five percent is only 20 pounds. If you are really serious about that, you can do 20 pounds in no time, seriously. Typically the heavier we start out, the more we lose early on. Invest this in yourself if it's really what you want.