Weight gain

I don’t know what to do anymore. I know it probably sounds dramatic, but my weight is literally making me feel depressed. I seem to be piling on the pounds, even though I’m eating less and exercising more. I feel like I’ve become the ‘fat friend’, my boyfriend works out a lot and has a great body and it’s making me feel like everyone is looking at us like ew why is he with her?? I don’t know how it’s happened, I’ve put one like 20 pounds in the last 7 months. I stopped smoking cigarettes which I guess contributed to it, I almost feel like starting again to lose the weight. It’s honestly soul destroying, my self confidence is non-existent. Please can someone give me some advice?