Black mould??update

So on xmas day I had to go to a client and they had black mould covered walls i felt fine before i attended the house. Anyway i was in the house for 30 minutes and within 15 minutes i started to go light headed and dizzy. It's now the 27th and I've had headache ever since, temperature keeps switching going really hot then really cold, feel sick, stuffed nose and extremely tired. Do you think this is from been in the house? Or I just councidently caught a cold? I told my partner and he told me to take effect from black mould I'd have to be in the house for days!

Picture is just off Google images but it was very similar to this. Also the client has full capacity and chooses to stay like this until his health really deteriorates or he gets dementia etc that's his choice of living unfortunately.