That's what friends are for. Or some family.
Hm..you can always blog your problems.
Or just use this Yahoo answers thingy and vent- if you want advice you can just tell them u'll give them 10 points for the best advice.
Depending on what it is im sure you can go to any chat room and just 'go off', you can be like:
OMG Im so fed up with this brat..
(or) I hate my stupid dad
im sure someone will say something sooner or later.
Best suggestion is blogging or posting it like on FB or something.
Take care
((