every time I fill my cake with buttercream or creamcheese filling I end up with "seeping" out the sides. I put in a dam and I dont put it all the way to the edge, but it makes its way there. please help. It is so frusterating.

Maybe your icing is too thin. Try making the dam with a stiffer icing.

Try letting the cake settle for a couple of hours between filling and icing or after filling and crumb coating.