How to alter Delay - Wet/Dry and Reverb - Wet/Dry via node on a pictslider

I'm trying to create a patch in which the Y position of a node within a pictslider changes the wet and dryness of a Reverb and the X position controls the wet and dryness of a Delay. I would like for it to be so that when the node is at the top right corner of the pictslider both the reverb and delay are on maximum wetness, and when at the bottom left they are both on maximum dryness.

I have attached what I have done so far but to be honest it will probably just throw you off as it is so far from the right direction.

Any help is deeply appreciated!

Thank you