I would talk to your OB or midwife. When I realized I was suffering from it 5 mos pp, I called my midwife first, and she was able to help me find good psychiatrists that were under my insurance plan (that's how much they see this -- they know all the psychiatrists in the area!).
Personally, I would recommend counseling and medication. Both are important in my experience, and I would not be doing nearly as well if I were only getting one or the other.
I would also recommend seeking help as soon as possible. It's very normal not to realize you ahve PPD until 5-7 months pp, but when you do, prompt treatment is important. The sooner you're treated, the better your chances for a complete recovery and the easier it usually is to recover.
Remember, roughly 400,000 women get PPD every year! It is incredibly common and nothing to be ashamed of! I have shared my PPD/PPA quite openly (even with people I don't know all that well) and have received nothing but love and support. You'd be surprised how many people even confided in me that they've been through the same thing! You have a ton of "sisters" who've been through the same thing, and are cheering you on!