I feel your pain and I also understand where you are coming from.
I also do not talk to my family about my present problems but I will have to this week because of social obligations that I cannot deal with right now and I just have to hope that they will understand, and if they dont, I will deal with that too.
But you mention that you have friends and family who care for you, if they are present they might be aware that you are going through something and might be afraid to bring it up, maybe therapy might help you.
I have been on anti-depressants also and they stopped working for me so I am working with my doctor to find something that will help my current state.
I also understand how having family who cares helps you to keep on going, during hard times, the thought of my 2 daughters has kept me alive.
You are very lucky to have people who love you, dont ever forget that!
I hope you soon feel better and although I am struggling myself these days and do not pretend to know what you should do, I do beleive you should talk to someone.