hi, you are complaining of left arm numbness
which probably because of compression of nerve
in your neck due to disc bulge.
now this is not a serious problem this is just a process of spinal degeneration or wear and tear of joints and disc of spine.
you took epidural injection but not get relief with it thats ok because inj. is just like jack-pot may work or may not be.
your current problem not coming from epidural injection.
first you have to do MRI of cervical spine
with screening of whole spine and accordingly we can proceed further.
till then continue physiotherapy
and multi- vitamins tablets.