ahhh its ok probably the best thing আপনি can do for him is just be there try to make hime laugh অথবা get him choclate. just let him know that your there and আপনি care
I guess it all depends on what do আপনি both feel for each other.If there's আরো than just friendship between the 2 of আপনি even remotely possible,perhaps your gay friend would even shift to bisexuality.Who knows what might happen between 2 best friends?