Indigestion and constant burping!

Your oxygen absorption is low. Take your blood pressure, it will also be low. Try nitric oxide supplement $10 Walmart start slow it is totally natural but hits hard at first when your weak and have a lack of oxygen in blood. Take with food, the buzz is needed oxygen, not caffeine. It totally helped me.

All the burping is air you're swallowing when you salivate or vomit, it feels stuck in your chest because your blood oxygen level is low and your lungs don't have enough blood flow currently to properly expel the trapped air. Foul burps and other gas is methane fermentation gas from the slow/non digestion in your stomach. Take a good laxative and once you clear out the rotten smell burp/gas will go too. You have to keep the bathroom process going or the rotten stuff will come back. Probiotics, less gluten, stool softners and high PROTIEN diet will help the rotten stuff. Up your bodies oxygen absorption with nitric oxide supplements to increase blood flow. You won't pass out anymore, your heart palpitations will calm and you will be able to breathe deeper with less swallowed air burping. Your brain and thoughts will be clear again with the oxygen help. Read up on it.

When you oxygen is low it affects your brain function. You can behave like someone with ADHD/ADD. Up one minute (or all night) and crashed the next. Buy some nitric oxide supplement and sip some Gatorade for electrolytes. You'll feel normal (brain wise) in a day or two.
If you're shakey from low blood sugar, then the heart palpitations may be from high blood sugar. Go to Walmart, buy a cheap blood test machine (store brand) and check yourself. 75-150 normal. Higher or lower go to the doctor.