Brief Answer:
Hiatal hernia the cause here

Detailed Answer:
Thank you for asking
Hiatal Hernia is the likely and most probable cause.Small bowel bacterial overgrowth, gastric bile reflux or acid reflux are frequent benign causes of nausea, vomiting and retching. Metabolic causes such as hyperglycaemia, hypercalcaemia, renal impairment, and Addison's disease need to be excluded. Gastroparesis and slow upper GI transit can exacerbate symptoms. Oesophageal motility disorders such as diffuse oesophageal spasm or ineffective motility can develop. Oesophageal strictures are another important cause.

But your most likely cause is hiatal hernia and it needs a fixations. Its causing all the symptoms.
Here is the management plan.
treatment goals include the following:

Prevention of reflux of gastric contents
Improved esophageal clearance
Reduction in acid production
In the majority of patients, these goals are achieved by means of a combination of the following:

Modifying lifestyle factors
Neutralizing acid or inhibiting acid-producing mechanisms
Enhancing esophageal and gastric motility
If iron-deficiency anemia occurs, it usually responds well to proton-pump inhibitor (PPI) therapy.

Surgical treatment involves removing the hernia sac and closing the abnormally wide esophageal hiatus. It is necessary only in the very few patients who have complications of GERD despite aggressive PPI treatment. Potential surgical candidates include the following:

Young patients with severe or recurrent complications of GERD (eg, strictures, ulcers, or bleeding) who cannot afford lifelong PPI treatment or prefer to avoid long-term pharmacotherapy
Patients with pulmonary complications (eg, asthma, recurrent aspiration pneumonia, chronic cough, or hoarseness linked to reflux disease)
The 3 major types of surgical procedures that may be considered are as follows:

Nissen fundoplication (or a variant, the Toupet procedure)
Belsey (Mark IV) fundoplication
Hill repair

Get to a gastroenterologist and let them help you with it.
Take good care of yourself and dont forget to close the discussion please.
May the odds be ever in your favour.
Regards
Khan

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