Accidentally wiped system but still can boot into recovery. topic

I was being careless when flashing a CM12 ROM and accidentally went and wiped my whole phone including the ROM that was already on it. So now when I turn my phone on it just shows the Samsung Logo with the CyanogenMod Robot and then just goes straight into recovery. But since I can still boot into TWRP means that there still may be hope yet. However when looking on XDA about people who had done this as well you have to be able to plug your phone into your computer and flash the factory ROM on your phone. I cannot do this because the USB port on my S3 is not working and hasn't been working for a while now so I cannot use odin to flash a ROM.

The only way I could possibly do anything is if I take the microSD card and put something on it and do something with that.

Is there any hope for me or will I just have to brave using an old iPhone 4 until my upgrade comes up in May?