thank you for your query.
Your symptoms point towards Phlebitis
.Phlebitis is the inflammation of a vein,it most commonly occurs in superficial veins.
it will cause -
Pain or burning along the length of the vein
Vein being hard and cord-like
the most common cause for this is the intravenous catheter.
the treatment includes-
*NSAID's for pain
ointment to be applied only at the site of redness
*avoid lifting weights or overworking the arm
with the use of the ointment the symptoms should come down in 5-7 days.
hence no need to worry.
wishing you good health