a lot of guys will recommend this or that which is fine but i would focus more on rest and look into 'graston technique'. you can literally use a spoon on your forearm and release a lot of blood and tension that way. look at the youtube videos
Deca will just lubricate and mask the pain for a while and could cause further damage. First I would check with a doctor to figure out what is causing the pain then try to find a fix for it.