ZenFone 2 (ZE551ML) - Won't continue past AT&T logo at boot ~ Please help!

This phone is nearly 2-3 weeks old, I had been transferring stuff over to a sd card cause I had filled up the internal space so quickly. I than realized that I had certain apps still downloading to my internal storage and it filled up to near capacity and the OS began to misbehave, ASUS launcher would not respond and crash, as well as various background applications as you would assume would crash due to low memory allowed. Before I had a chance to delete or transfer anything more ASUS launcher kept crashing repeatedly so I restarted it. At first it came back on with a blank screen but I could feel the pattern to unlock the encryption during the boot, so I hard restarted it, and it will show the first AT&T logo then allow me to decrypt with a pattern then it goes to another AT&T logo where it just sits, it doesn't freeze you can see the subtle animation of the logo, but it doesn't proceed any further. When I go into recovery I'm only allowed 3 options, restart, update via adb, update via microSD, there is no factory reset, or clean cache.? :( In fast boot mode I'm presented with the following information if it is of any use:

Product_Name - ATT_Phone
VARIANT - ASUS ZenF
HW_VERSION - 4
BOOTLOADER VERSION - 2.52
IFWI VERSION - 91.37-DEV
IMEI - 0123456789ABCDEF
SKU VERSION - ZE500CL_EU_US
SECURE_BOOT - ?

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Any advice or help would be deeply appreciated, I'm going to try and reinstall the firmware or upgrade it, but is there any way to wipe the cache with fast boot? Or something else I'm not thinking of? Thank you.