Welcome to HCM.
I appreciate your concern for your husband's health.
The belching and acidity are due to acid peptic disease
. It may be related to the stress of moving into a new environment or due to a bacteria called H. Pylori.
Hypohyroidism can worsen one's mental health.
I think he should see a doctor, restart Synthroid if his Thyroid function tests
show that he is hypothyroid and also be investigated for H.Pylori.
For relief of his acidity and belching, a proton pump
inhibitor like omeprazole
may be more effective than Zantac.
These days it is possible to keep in touch with your doctor through Telemedicine
Dr. Noble Zachariah, Kuwait.