i thought i forgot to take my pills or something

what

The reason why gaze is bad is because it is CA negative. You spend a card to get nothing in return. As I said above, you don't need to "build around delirium" in this deck per-se because you can get delirium very easily. This is why graveyard enablers like scour, consider, gaze, etc are just straight up bad in shadow decks; you don't even have a big threat to delve away spells with like Murktide does, the closest thing would just be Kroxa. DRC and Shredder are different because they are both threats and enablers.

The only other payoff to filling your graveyard quickly (besides kroxa) would be Underworld Breach which you aren't even running. I definitely agree with Sef that running at least 2-3 copies is probably correct here.

Not running 4 Expressive Iteration is almost definitely suboptimal.

A deck like this is able to achieve delirium fairly easily, so running cantrips that help full the yard like Consider and Thought Scour aren't really needed (which is why the MH2 era shadow decks never ran scour, while the old ones with Gurmag Angler did). You should be able to get Land + Creature + Instant very easily, and there are 13 Sorceries + Artifacts + Enchantments for the fourth type. Instead of running cantrips, it is probably better to just increase the general card quality by running better cards. 4th Drown, 4th heat, Inquisition of Kozilek, or the aforementioned copies 2-4 of Iteration.

I assume you have some sort of reason for not running Ragavan, Nimble Pilferer? It is probably one of the best cards you can cascade into.