You have described your symptoms very nicely and from the description that you have given, it appears that you have developed thrombophlebitis
- an infection of a vein. This can occur after an IV is inserted and generally spreads along the vein path. You will feel a cord like structure along with tenderness along the vein.
Generally it is self resolving and and all you need to do is take some rest, take paracetamol
if its painful and apply thrombophobe -a heparin
ointment which will reduce the problem. If the pain persists please dont hesitate to see a suregon who can examine it and opine you better.
Hope I am able to solve your concerns.