You need to add some hourglasses, but not too many. I only use 2 in my 46 card deck.
Bone Wall is a must. Rain of Fire is too.
Also, it is almost not worth using Hourglasses if they are not upped. The change of cost from 2(unupped) and 1(upped) makes a lot of difference.
And if you don't have Eternity, you shouldn't really try to farm FGs with a control rainbow.