Hey budha, my story is similar to yours. I'm even in your area so I can share some good info. MJ helps with my depression and anxiety, among other things. I didn't start smoking until I was 23. Smoked for 4 years and took over 2 years off to see if there was a difference, and to give the doctors a shot at helping my medical conditions. Unfortunately they're a bunch of scripted/cookie cutter morons so conventional medicine has failed for me.
I got my MMJ recommendation at Medicann in Long Beach.
MediCann | A Prescription For Change
It was $110 I think and you should bring in your medical history or if you have some prescription medication bottles that are recent, they'll work too. As long as you have a medically diagnosed condition that MMJ can help with, you'll receive a recommendation. The MMJ doctor will provide consultation and go over the risks and benefits. It is a regular doctor visit, except with alternative medication.
The OC sucks for dispensaries. They're WAYYYYY more expensive than any other area, and theres very few of them. They even have delivery services so you can get your meds like you were ordering a pizza. Again, they're wayyyy expensive. LA and Ventura county have dispensaries all over the place and are much cheaper. LB has a lot of dispensaries also, but prices aren't that great. You'll find that MMJ is more expensive and not always any better than what you're used to. Selection is usually great, but quality is very subjective. Some of the worst stuff I've ever had was from MMJ dispensaries.
You will want to go read up on
California NORML | Dedicated to reforming California's marijuana laws! for the laws, doctor lists, and dispensary locator.
Now that you've got a lot of good info, good luck!