If you don't want to get a taxi could try bending i back. I have bent many a wheel back into somewhere-near-true (at least will fit in the frame with the brake loosened) to get me home after crashes at polo. Try taking it out and bending it back with you hands against a wall or standing on it on the ground using the axle as a fulcrum. At the moment the spokes will be very irregular in tension but when you bent the rim back towards true there should come a point where the rim 'pops back' to a point where the spokes resume similar tension all the way round. It might take a few good bashes with your hands. As it's a back wheel it should be strong enough to get you home on. Doing this to a front i wouldn't advise. Of course only do this if you feel confident enough that you can ride without a back brake and aren't too shook up from the crash
When rebuilding, check the holes in the hub haven't been damaged by strain from the spokes. Should be fine if not damaged
Hope your not too badly hurt.
If you don't want to get a taxi could try bending i back. I have bent many a wheel back into somewhere-near-true (at least will fit in the frame with the brake loosened) to get me home after crashes at polo. Try taking it out and bending it back with you hands against a wall or standing on it on the ground using the axle as a fulcrum. At the moment the spokes will be very irregular in tension but when you bent the rim back towards true there should come a point where the rim 'pops back' to a point where the spokes resume similar tension all the way round. It might take a few good bashes with your hands. As it's a back wheel it should be strong enough to get you home on. Doing this to a front i wouldn't advise. Of course only do this if you feel confident enough that you can ride without a back brake and aren't too shook up from the crash
When rebuilding, check the holes in the hub haven't been damaged by strain from the spokes. Should be fine if not damaged