Have you tried using a Trap Bobber? Those make a huge difference. It should make fish significantly easier. Also, how do you know it's a Sturgeon and not something far harder? A Sturgeon is only 78. With the normal (not the super easy) mod, I've found that Pikes (60) hover almost in place and barely move. I can't imagine that a 78 fish with this mod being that much harder to be honest.