Hi and welcome to Healthcare Magic. Thanks for your question...
From the symptoms you have described, you appear to be having a "thrombo-phlebitis" (i.e. inflamation / thickening of the vein). Simple home remedies
like hot or cold
compress, keeping the affected arm elevated on pillows, taking adequate fluids and getting as much rest as possible, can help to a certain extent and it may take a few days for the swelling and thickening to resolve. However, since these don't seem to be helping you much, it's better to have yourself examined by a doctor. In case you develp fever
or if the arm becomes red and warm, then it means that you are developing complications and you need compulsory medical attention.
Wish you all the best.
Dr. Jonas Sundarakumar