There can be a clot busting injection at the site of the clot if urgent to prevent any major damage to the tissues for lack of blood/oxygen.
If it's a clot you should really be on clot busting medication to hopefully remove it. If the pains get worse I would seriously get it checked out because you can suffer major tissue damage in the limb if the blood supply is inadequate. Using the gel is simply relieving the pain but not dealing with the issue.
Thanks for info its a lot better using deep freeze cold gel
The pain could be due to thromboangitis indicating inflammation of the vessel and that condition can lead to ischemia (lack of blood flow) to the arm tissues. The fact that the cardiologist could not progress with the arm vessel indicates there had been a problem and may have injured the vessel and that injury has clotted causing the pain.
Does your arm look reddish?