I am surprised by the double standart I see in the behaviour of your husband. Well, maybe not suprised, I tend to have a similar problem, but I am aware of it. Does he know that this might be not fair? That it seems as if it is OK for him to love another person but it isn't for you? Aside from who it is, or is his issue that it had to be his friend you fell in love with?
And don't feel responsible to hide your tears. I cry easily, I need those tears to relieve the stress I feel in the specific situations. I know that some take tears as an aggressiv act that should make them feel responsible or at fault. But it isn't like that most of the time, at least not for me. I am not sure if this is the thing for you as well, but maybe it would helpt to explain to your husband that you are not accusing him if you cry, that you need this to deal with a painful situation and the pressure you are feeling. That you don't cry for the sole purpose to make him feel bad.
Good luck, don't give up. Wishing you some happier moments in the future.