I've had men pick up on my depression immediately too. How to fake it? Sometimes you can't. You live it, feel it, it hurts. It shows. I tried hiding it. I'd only cry in my room. I don't think my parents ever knew how badly everything affected me.
They didn't include me either in things, and many girls in school avoided me, or they'd do the cat fight thing. I don't get people in general still. But I kept one girlfriend, and never had any guys as friends until one this year. Yes I think some people are able to see the depression no matter what you do to hide it. WOrking through it is the only thing you can do. Are you still working out? Exercise will help. (even if you think in some ways its worse)...

One guy I met in a bar when I was young, closer to your age, had the most beautiful smile that he attracted my eyes to him. He told me a year later, "I knew you were depressed"... I had wanted him, he tried to get me to date his friend. I guess I knew too, I wanted friends that were upbeat, positive, and healthy. Sorry to go on, this is your thread, just felt like telling you I know what you are saying. There is a saying "fake it til you make it"...There may be some truth to it. Hang in there friend.