really stiff rear suspension?

[97LowRanger]

hey guys i have a 97 regular cab ranger 2wd 5 speed i lowered it with the 3/4 kit replaced front i beams and flipped rear, i replaced rear shocks with the lowered DJM Suspension Calmax SuperShox Shocks, from summit. The problem is that when i jounced the rear it bottom out so i cut the bump stops in half im guessing i have about 4" between the axle and the bump stop, the rear end feels too stiff, as if the truck was not heavy enough, i live in apts and they have speed bumps i drive over them slow and the rear just feels solid, there is no moving at all also on the street feels like that i think its normal from the truck actually going pretty fast, but not in speed bumps driving really slow it feels solid anyone know my problem???
my biggest doubt is if the shocks are way too stiff,if anyone knows specifically which shocks from Nissan fit let me know, thanks.
please help lol im tired of the way it rides im pretty sure i dont need a c notch although i will probably get one later on.