Your three main variables when bowing are bow speed, weight (downward pressure) and distance from the bridge (contact point). Try slowing the bow speed down and bowing slightly closer to the bridge on the A and E strings. The bottom E is only vibrating at 41.7 times per second and the string has to be heavy to do this. Bow speed will be progressively faster (use more bow) as strings become thinner and vibrate faster.
Have you ever dragged your fingernails down a school blackboard to produce a horrible continuous screeching sound? If so you have set up a relationship between fingernails and blackboard, based on speed and pressure, that produces a resonance.
Listen and feel for resonance and back-pressure on the bow as you slow down. Look for maximum sound and resonance for minimum effort from you as you hunt for the right combination of bow speed, weight and contact point. I would probably use less than half the bow length for medium pace quarter notes on the E string. As notes get shorter and faster I gradually bow closer to the fingerboard for more string flexibility to control note starts, otherwise the bow starts to skid.
The slightly thinner A string moves more easily and you have some more latitude with the three variables, yet you can still find resonance. To my mind it is not just trying to move the string widely with the bow. You can do that bowing quickly over the end of the fingerboard and you still won't create a strong rich "chocolate cake" sound.
Your difficulty could also be that your bass is poorly set up and favours G and D too much, needing a sound post workover?
Happy hunting......
DP