How long does it take for your body to go into alcohol withdrawal?

How long were you "clean"? The reason I ask is that it will have a direct effect on the length of your withdrawal. Unlike most other drugs, alcohol is metabolized in a steady-state, linear fashion from the body. Another interesting characteristic of alcohol is that it, unlike most other drugs, results in immediate physical dependence, that is why people have hang overs.

So yes, you are in withdrawal. The question of severity will depend on the length of time you were not using before your relapse and the amount you used after you relapsed. Please note, alcohol withdrawal can result in delerium tremens and seizures and as such can be dangerous, even fatally so. If your usage has been severe you should seek out treatment. You will need an anti-convulsant such as a benzodiazepine as soon as possible. If you have any (Xanax, Ativan, Valium), take one straight away and go see a doctor.

Well you can just go back and tell them that the detox programs didn't work out and you once again drank. They will help you understand what you need to do. It would be either getting back to the detox program or some tips, depends though.

All the best.

usually within 24 to 36 hours after the last drink

It depends how heavy a drinker you were to begin with. I haven't drunk alcohol in almost 3 years but I wasn't a heavy drinker before that.

Those are withdrawal symptoms. Alcohol hangovers in normal people don't involve shakes. Please go back into the recovery center and get the help you need.