what treatment service do I want?

If you want to control what you are using or cut down, there are a number of options you can try:

Withdrawal programs - as an outpatient, in a hospital, in residential units, a nurse visiting at home, with your general practitioner.
Substitution pharmacotherapies - for example methadone, subutex or suboxone for heroin.
See a counsellor who will help you form a program that will meet your aims - for example a controlled drinking program or relapse prevention group.