Answer: For right now, I'd set a crutch of sorts under the limbs to help hold them up and keep them from breaking under the weight of the fruit. Two by fours come in all kinds of lengths so I'm sure you can find the right size to wedge under the branch to keep it upright. You might want to remove some of the fruits to lighten the load. Although you won't be able to use the fruit, you will be doing your tree a favor and you may be able to stop further damage to the scaffolding branches. Along with removing some of the excess fruit, your tree might be in need of remedial pruning.
To avoid the droopy branch problem in the future, try thinning out the fruit when it is still small. If you remove every other fruit when it is just an inch in diameter the tree will have fewer fruit to support and those that it does mature will be juicier and more flavorful.
Good luck with your tree!
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