Ouch.
Just guessing, but in my opinio, the best option would be to replace the mast. If you can find a place that sells/repairs used boats, they might have a mast that's close in cross-section to yours. If it's too long it can easily be cut down. You can probably remove and reuse all the hardware from your broken mast.
I've heard that some places will splice a broken mast back together, but it seems that all the labour involved there would make that option about equal to just replacing it.