hey there, I'm not sure how old you are. Normally I wouldn't ask on an online forum but it would be good to know if you're living with your family *guessing you are* or not.
Is there any way you can get to a doctor without them knowing? Maybe you can go to your general doctor and talk to him/her and see if they have anything to say about it?

You could also approach your family about it. If this is depression talking, it's no YOU who is a "sad person", it's just that you have a medical condition that's MAKING you sad. It's important to remember this.

I understand your reluctance to tell anyone about this. I was the same way. But it's VERY important to get help when you need it - I've learned this the hard way.

Keep posting, here or in the depression section, best of luck