I took a ranitidine pill at 2 am it's is now 5 am and i still have heart burn and can't sleep what should i do?

Gastritis?: Might need to visit your doctor in the morning, but meanwhile try glass of cold skimmed milk with ginger, peppermint or caraway.

Many things: Take another one. Prop up or get out of bed as the upright posture helps and lying down makes it worse. Take antacids, alka-seltzer, or just try eating some food to buffer the acid. When the stores open, buy some Prilosec otc and take it for a couple of weeks. If persistent, see your doctor for further testing.