A) Turn in the idle screw on the throttle linkage to get you to the shop, use caution here as this isn't the best choice should you have, slow reaction times.
B) Gather shoe laces from the neighborhood kids, they don't use them anyway and make a temp "exterior" you pull it throttle cable
C) Same group of charming kids, offer free ice cream if they'll push you to the repair shop.
Seriously, replacing the cable yourself is easy, it's a 1/2hr job at most.
Pull the old cable out from the tunnel tube being careful as it will be full of grease.
Remove the broken cable end from the carb linkage.
Check and confirm that the new cable has the same style S hook as the old cable has.
Wipe a small amount of grease on the cable as you feed it into the tunnel tube.
Insert the S hook onto the pedal arm.
Slip the cable stop over the new cable and adjust it at the carb linkage for full travel i.e full throttle position while confirming that you have idle position........ before starting the motor.