If you can act 'normal' around your mom, can you act normal otherwise? How about
talking to your shcool counselor? That is another option. Depression is really hard to hide. I really suggest that you talk to somebody, if not your mom, how about
a friend or relative?
best wishes,
Karen
Here are some other resources that you might like to try.
http://www.teencentral.net/
http://nineline.org/
http://www.teenhut.net/
http://forums.teenhelp.org/
You might find that some of these sites are helpful too.