my guess is what you have here is cubital tunnel syndrome
has nothing to do with AAS really, more to do with imbalances in your arms.. lifting weights, and you probably work a lot with your hands.
when you workout and bend your arms you cause a pinching in your elbow, which causes that numbness in your hands. also if you sleep with your arms bent, or work with your hands a lot it will make it worse
AAS may make it worse simply because you are lifting heavier and more often putting more pressure on the area, but no direct link
you need to strengthen the top of your forearm. go on youtube and find exercises to help with this condition. you need to floss daily to help relieve pressure on that nerve. if you do not fix this you can get permanent damage to your arm/hands. and if it doesn't resolve itself within a few weeks you will need surgery where they take out tissue and bone from your elbow so it doesn't pinch the nerve.
you may also want to invest in a cubital tunnel brace and sleep with it. you have the early signs of the problem so time to stop it now