Market losses in and of themselves are not the grounds for litigation against a financial adviser in most cases. You must be able to demonstrate negligence, fraud or other wrongful conduct. Now, if this person is an "adviser" as opposed to a stockbroker, you may have been owed fiduciary duties that are higher than that owed by stockbrokers. In any event, if you believe you have a case, the best thing to do is to speak with an attorney who handles securities arbitration and litigation to evaluate your case. As one commentator noted, you have arbitration obligations that will require your case to be handled before FINRA.
Happy to assist further.
The foregoing is not legal advice nor is it in any manner whatsoever meant to create or impute an attorney/client relationship.
I'm unclear whether the adviser said his head was buried, or that yours was buried.
You may have grounds, but I think it would be a rough trail to hike to demonstrate his actions and advice were so contrary to reality as to be the primary cause of your losses.