You are all over the place. My best diagnoses is that you lack the strength to pop a stiffer deck. The Merc is the entry level deck from Flow. The Breast board you rode is a limited graphic version of the Rush, my personal favorite all mountain twin. It has carbon, the Merc doesnt.
Look into the Era, Salomon Sabotage or a Villain, Arbor Westmark, or a Yes Jackpot.