If you are suffering a gallbladder attack they can last for 4 hrs. It is an excruciating pain but by the time you get to ER, get examined, it will be over. So you have to tough-it out.
You need to get relaxed.
After 4 hours, thats around 4.00AM from you timings. You can take the Epsom Salts but it needs to be on an empty stomach.