I'd go to a government hospital,tell the doctor the symptoms, and pay the 100bht fee.
Wellness checkup for 10kbht is a pointless scam.
CT/MRI scans are a scam.
Faddy diets also a scam.
As you said in the op, similar wellness checkups in the past found nothing, that's because they're scams.
If you're 20lbs overweight, eat less, exercise more.