How to wire a single toggle switch/outlet in a GFCI circuit
The circuit as you have designed it will not work. You have routed current from the load hot terminal of the GFCI through the switch and load, then back to the neutral node in your service panel, bypassing the load neutral terminal of the GFCI. The GFCI senses this imbalance and trips. 

You cannot mix a GFCI protected path with an unprotected path. You must either power the toggle switch and LED load completely from the GFCI load terminals, like this: 



or power the toggle switch and LED load completely from the unprotected mains supply, like this: 



One path or another will require a 12/4 w/g instead of a 12/3 w/g cable.