Unhappy [Q] Galaxy s3 wont allow me to store anything on internal SD card

Two days ago my phone (samsung galaxy s3 sgh-i747m) just froze out of the blue. Upon restart it would get stuck on the samsung logo and the blue led would keep flashing. I tried flashing but it kept failing and I kept receiving an error message concerning "/data". It also at first did not let me go into recovery mode untill I did a samsung kies recovery.

The phone was flashed and rooted months ago.

After much reading I decided to do a factory reset and cache wipe. After that i was able to flash 4.3 unto my phone.

Here comes my new problem.

I cant transfer anything to my internal sd or download anything to my phone. Also its the 8gb version yet when connected to pc it says its a 16gb device. I'm thinking something is up with partition on the sd card maybe.

Anyways I picked up a sd card today and am wondering if I can wipe the internal card and reflash and start over?