Hello,
The bloating and feeling sensation along with nausea can be due to gastritis after the
hangover. Take some OTC antacid like Mylanta.You can also take zantac(ranitidine)or prilosec(omeprazole).These will help. Also keep your fluid electrolyte balance optimum by drinking lots of fluids.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided.