BE CAREFUL!
Your biggest potential problem is that you lied on an FAA medical form and then admitted to it! That is not an FAA administrative issue, that is a federal felony (people have gone to jail for this under certain circumstances). Legally there is no such thing as "forgetting"...only "lying". You REALLY need to talk to a laywer BEFORE you talk to your AME of the FAA, or fill out another medical app.
I understand the AME was saying he could smooth it over with the FAA...odds are that he is correct. But there is no guarantee on that if the wrong fed gets a look at your case...better safe than sorry. The FAA could revoke (not just supend) all of your pilot certs for this, and then refer you to the justice department for your criminal charges.
Your biggest exposure woud be if you were flying during the period when you had this problem...if you self-grounded, you are in better shape. But I am 99% sure that a decent lawyer could arrange everything so you do not have any issues in the future.\
The FAA recently did criminal charges against a number of pilots in California who were drawing social security disability...they did this by matching federal databases. But worker's comp would be a state issue, and I'm sure the FAA doesn't have the resources (or the authority) to look at every state/local database.
I think your risk of getting in trouble comes from admitting it after that fact...the good news is that it looks like you have good intentions so I don't think anyone will hold it against you. But you want to do everything you can to protect yourself.