Replace 8 amalgam fillings with composite/ceramic ones?

I have 8 Amalgam fillings done over the past 15 years (one root canal).

In the last few months i have been thinking that these might cause my illness
Apart from the tooth decay underneath, I have good healthy teeth and good dental hygiene.
I would like to have them replaced,My question is what should I replace them with,a white composite fillings or ceramic.

I would greatly appreciate any advice. Tweet