It sounds like you are doing everything you can! Leave the branches tied up and care for the plant as you had been previously. Hopefully, the plant will become strong enough to hold its branches up again, though they may be too heavy at this point and could always need support. To give the plant an extra boost, feed it with a liquid cacti and succulent fertilizer, following the dosage instructions on the packaging.
It sounds like you are doing everything you can! Leave the branches tied up and care for the plant as you had been previously. Hopefully, the plant will become strong enough to hold its branches up again, though they may be too heavy at this point and could always need support. To give the plant an extra boost, feed it with a liquid cacti and succulent fertilizer, following the dosage instructions on the packaging.