Better Base = Lower Hips

One thing I would like to make note of, is that when I first came back to rolling I noticed that I would fight to escape and get on top, only to be swept fairly consistently. What the heck is wrong with my base? One thing I have been told to do more is to keep my hips lower. I of course try my best to really focus my weight from my chest to their chest, but that isn't enough. I also need to focus on keeping my hips connected to the ground and really force my weight downwards. My hips should not be over them, they should not pushing into them, but they should be driving down towards the ground and as low as they are. I'm hoping this will help me not get swept so much when in side control!