Hello
I share your concern
Looking at your description it seems to be related to food poisoning, indigestion,
hyperacidity triggered by grilled meat.
I would advise you to take antiacidity medicines like
pantoprazole or ranitidine group of drugs with antacids for 2 to 3 days.
For back pain I would advise you to do stretching exercises and
physiotherapy, if it doesn't help than you can take painkiller like diclofenac with
muscle relaxant liek tizanidine/chorzoxazone.
if it persists or aggravates further than you should
consult a gastroenterologist for an ultrasound or an endoscopy if need be.
Meanwhile have fresh fruits and boiled vegetables/ egg in your diet.
Avoid spicy and junk food and carbonated or caffeinated beverages.
Hope I could answer your question, please do let me know if you have any more queries, I will happily answer you.
Best wishes