I'm going to take a guess here and say I believe I've been following your situation on the BritishExpats site.
The guidance you have received on that site is solid. You have income which was not declared, and should have been, and information forms which were not filed. IMHO, the Streamlined Procedures are the best for you, even with the 5% penalty. As has been noted there, you do need to assert your position as to the bad advice you received, both with the IRS (they will want to know) and compensation from the 'expert' advisor you used (who should have insurance to cover such situations). As was noted on BE, did you have a contract? If the advisor continues to refuse to acknowledge a mistake was made,........(I'll leave that up to our local experts to comment on as to how to proceed).
EDIT to add: There is another method, but it is risky. You could file FBARS late and note as a reason "I didn't know". You would then file accurate amended forms 1040X for the years where the income and information (for 1040 purposes) was not included. As a result, you may get by OK, or you may find the situation worse.