Trying to install a medium-heavy bathroom cabinet in an old house.

Walls are old plaster and lathing.

In the inside of the cabinet there is a board about 1/2 inch thick at the
top. I have to get through that
then the plaster and lathing. Trouble is I screwed up and have a 5/16 inch
hole through the little board
in the cabinet and same in the wall and lathing trying to install those dry
wall anchor which did not seem to work.

Now how do I get the thing secured to the wall?

Thanks.