I m suffering from gerd after my dinner when i lie down to bed my stomach starts paining, acid starts building gas which cause reflux wht should i do.

This is a common: Problem for busy young adults. First, you need to make sure you do not lie down to sleep until 2hours after dinner (which can be challenging if you work long days). Have 5 smaller meals throughout the day, don't have your largest meal at supper if possible. Avoid high fat meals. You may also raise the head of your bed by placing blocks underneath to reduce symptoms. Also get checked for H. Pylori.