Haven't had experience with Ketamine, but I have had the experience of physical dependance on alcohol, and getting off it was hell. You sound like you could use help with the detox period. There are medical and non-medical supervised detoxes. Medically supervised detoxes have Dr's and nurses, and may give you other safe drugs to help with the withdrawal symptoms, while a non-medical detox is just a safe place to stay where you can't use while you get it out of your system.

Once you've detoxed would you consider treatment? Would going residential or doing an intensive outpatient treatment be possible for you. I know it sounds drastic, but you've been doing drugs a long time, and it sounds like you have a serious addiction. Rehab can be very helpful.

Finally, I would encourage you to get in touch with N/A in your area & go to meetings. It's really hard to give up any addiction without support, and 12 -step programs can be really helpful.

Good luck.

--splitimage