Hi Koala,
I hope you are doing better. I want to second the exercise and journaling recommendations. Getting your heart rate up is key: it really changes the brain biology and opens things up. Motorcycling is great, but frankly, running or bicycling is better. Journaling helps externalize thoughts and give you some perspective on them. In my experience meditating is even better for this, and it is something you can access at any time. It can help a person see the negative thoughts as just thoughts, something going through the mind that one can latch on to, or choose instead to just observe and let pass. It has worked wonders for me. If there are any meditation or buddhist centers in your area, their classes, dharma talks, or sessions should be free, as it is a Buddhist principle to give freely. Buddhism is not like a religion in the typical western way, it's very low key and non-coercive. I can also give you a couple hundred book recommendations, but the one to start with is probably "The Mindful Way Through Depression," which both explains the science behind meditation and offers some techniques, as well as a cd with guided meditations. It's by Jon Kabat-Zinn and 3 other psychologists.
Another thing to check out is a "warmline." These are non-crisis mental health helplines staffed by people who themselves have a mental health diagnosis, so they can relate to what most people calling are going through. Their purpose is just to provide someone to talk to that will actually "get" what you're going through when you need it. I only found one in Ohio, in Cincinnati, but I can't imagine they'd complain about a call from Akron.
Cincinnati warmline: (513) 931-WARM or (513) 931-9276
There is a walk-in counseling clinic in Akron, where you can just drop in to see someone. They are also able to help work out financial stuff and refer you to a therapist.
http://www.portagepath.org/expect/
(I volunteer at a crisis line, hence the referrals.)
I'm an introvert as well, so I totally get why you're wary of doing group stuff, but after many years of avoiding it, I started, and it's great. It really helps the feelings of isolation and being uniquely defective that often come with depression.
I found it helpful when someone asked me if I would ever say the things I tell myself to someone I cared about. Try to be a friend to yourself when you are suffering. You deserve it.