Medical check

you go to a GP of your choosing. Just use google or ask for recommendations, but you'd need to say where you live and languages you speak.

You might want to try this: http://medicis.be/fr/bilans-de-sante/

Ask people you know for a good GP. Going through a GP is quicker than trying to find someone yourself. The GP will do any tests they think necessary or may just send you straight to a consultant at the hospital for further investigation. I hope you get sorted and feel better soon.

The CHS Help Line (02.648.40.14) can provide contact details for English speaking GPs in different communes.