You definitely need the assistance of an immigration attorney who knows both criminal and immigration law.
This is not legal advise and should not be construed as such by anyone.
Hey buddy! What effect state law has on your immigration future can be best answered by an immigration lawyer familiar with California law. No one else will know.
I am a pretty smart guy, but I do not know everything. My answers here come from the knowledge I carry around in my head--if you want me to look something up, you should come see me. Take any advice here as being general in nature. Please be careful with your life and make decisions that are smart.
Just like you retained a criminal attorney to review/analyze your criminal matter, and represent you before the court, you too should retain an attorney to answer the questions you are asking. I definitely will not recommend you travel outside the country as you are talking about a controlled substance crime. Get a copy of your criminal disposition, and seek paid help. For contacts to local immigration attorneys, I suggest going to www.aila.org.
Legal disclaimer: (714) 479-1000 Mr. Zapata's response to your question is general in nature, as not all the facts are known to him. You should retain an attorney experienced in immigration law to review all the facts in your case in order to receive advice specific to your case. Mr. Zapata's statement above does not create an attorney/client relationship.