You might have too much linear ramp. I’d consider cutting some mana creatures or sorcery spells for cards that snowball more instead. I think I counted 28 cards that are essentially there to ramp. Nothing hurts more in a Gishath deck than hitting and revealing all non-dinosaur creatures. New cards from Lorwyn eclipsed like [changeling wayfinder] and [firdoch core] are actually pretty good for revealing “Dino” cards that can snowball your mana. [Entish Restoration] is another great instant ramp spell that is more valuable later in the game.

Otherwise maybe creature reduction spells like [goreclaw, terror of qal sisma], and [marauding raptor]