Tile contractor here. It please stop and start over, you will regret it if you don’t.

You have this set up for a traditional “water in water out” system. 3 piece clamping drain and rubber bladder. First you need to pre slope your pan. Meaning you need to use dry pack mortar to form a shower pan under your bladder first, than put in your shower bladder, souround the drains weep holes in pea gravel, than use again dry pack mortar to build your shower pan. Concrete had no place in a shower for a lot of reasons.

You could go the more modern and simplistic route with a topical membrane shower system. Please Google “wedi” or or “Schluter” shower systems.

Currently your asking for mold and water damage issues