You will need to take the credit counseling course - with VERY few exceptions, EVERYONE does. The means test (a mechanical set of assumptions) looks at the past six months income, so you should not have a problem with that. Your reality is what will matter in your filing. As long as your actual reasonable and necessary expenses use up all of your income, you should qualify for a chapter 7. You should probably wait until after your 2009 taxes were due (April 15, 2010 - unless you filed an extension - then Oct 15, 2010), so you file 3 years after they were due, which would likely make all but your 2010 taxes dischargeable. Generally creditors can only contest your bankruptcy if they can show you fraudulently obtained credit from them, which is rare. You should use the attorney finder at www.nacba.org to find a good attorney in your area.
Yes you will need to still take the credit class, you should file sooner than later as you are correct in stating that the court will look back 6 months for your means test to determine if you qualify to file a chapter 7.
You do have to take the course. If you file now, you will pass the "means test" which looks at the last 6 months income. But your current, or forward looking income is also considered to determine if your filing under Chapter 7 is abusive under the totality of the circumstances. Given that your 6 month income is below the statewide median income, creditors are limited in their ability to move to dismiss your case, but in any event that window runs until 60 days after your meeting of creditors, which is about 4-6 weeks after filing. You should see an experienced bankruptcy lawyer as soon as possible. And yes, there are good lawyers in your area (we have an office in Greenbelt, for example...)