Based on the information you provided I don't think you have any chance of reopening the case. A full and final settlement is just that. Typically settling parties acknowledge and agree that they understand their injuries/conditions may get worse in the future but the case is still over. I can't speak to the merits of the settlement, but even if the attorney committed malpractice, it's too late to bring that claim too.
I would focus on your medical treatment and getting better,. Unfortunately re-opening your case and claim will be unsuccesful. By signing the release you gave away or waived your rights to seek or request any additional compensation regardless of any future issue or health problems. Any claim against the attorney may also be barred by the statute of limitations.
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