I recognize the ‘error’. I’ve been there and felt like my hands were doing gymnastics. It was anything but in control. The one thing that could make it easier is to emphasize that you shouldn’t really cast anything except for chain heal while SWG is active. Can I suggest not using your mouse to move. If you use for example WAD to move around (AD bound as strafe not turn did the trick for me) – you can use your mouse to change your vision point and perform mouseovers on frames.
Hopefully, this is helpful to you!