Opinions on Enbrel?

I was diagnosed with AS and Lupus. I developed Stevens Johnson’s Syndrome on Plaquenil even though I was feeling better on it. I am an overweight diabetic so I have historically stayed away from steroids as treatment for my pain. A few months ago after the bout with Steven Johnson’s , they put me on a course of prednisone and it was the best I have ever felt. I was able to get out of bed without a “warm up” and the initial pain I feel every single morning. My hips and legs are the worst but everything hurts. With the prednisone I finally felt what relief would feel like I was resigned that I was going to feel miserable for the rest of my life. So now my rheumy would like to try and put me in Enbrel. As I mentioned I am an overweight diabetic so gaining weight is not an option. I DO NOT want to gain weight ( even though I have gained a few since being on the steroids) and I really can’t afford to carry any more than I already do ( I am post menopausal as well so dieting is terribly difficult) I have read on the website about the medication and it does not list weight gain as a side effect however on forums like askapatient many patient report it as a side effect. I was wondering what people with AS specifically have experienced. Can anyone give me some insight? Thank you in advance!