My doc of one year doesn't know my history of substance abuse. i'd like to change docs and start over. should i start with a fam doc or a psychiatrist?

Hard to say: If you need a psychiatrist find one. They would not be available to treat your physical illnesses but could help you with the mental, emotive processes that make life hard. Some family docs are quite capable of helping you with common issues both physical and mental.Neither will be able to help if can not be open with them about your problems.

Medical Culture: I am on the side of starting with family medicine. There are addiction psychiatrists, but they would only deal with addiction and not the whole person or primary care of your health and history. Most doctors, not all, but many would not be judgmental about substance abuse. In my training in the small towns of idaho and utah there was a lot of addiction and alcoholism. The physicians were great.