This could be result of composite toxicity, not necessarily of amalgam ingestion.
Which composites did the dentist use?
It is important to understand that almost all composite materials exibit off-gassing which can lead to symptoms that you have described. Multi amalgam removal can often trigger new allergic reactions. Also, be advised that some of the composites are proven carcinogenic materials.
I advise against multi amalgam replacements, which are often times advertised by so called biologic dentists which can cause patients more harm.