Bloods, aromasin or letro (as a last resort if estrogen is super high).
Like stated above you have deca which can cause prlactin issues but also can aromatize and convert to estrogen (at a much lower rate than test), test which aromatizes, and dbol which also aromatizes.
Def get bloods though in the meantime get aromasin or id say increase your arimidex dose to either .5mg ED or 1mg EOD.