Everything will fall into place if you shift your focus on just trying to find ways to make things take less effort. Strong people struggle with jiu jitsu because they can overpower people early on and they exhaust themselves, but you need to learn the skills before you try to add strength

Most likely you are doing the technique wrong. However, keep in mind that not all moves are equal for different body types. First thing to always consider is that you are doing the technique wrong. That has helped me a lot through my journey.