Some further thoughts:
First of all, I know what you mean about the relief at having the problem finally diagnosed. That can really help, because then you can avail yourself of the resources to treat it.
For me, as for many with this sort of disorder, a combination of medication and talk therapy work well.
Therapy: My therapist's approach is eclectic, but when the social phobia/anxiety stuff comes up, we work on cognitive behavioral skills. She also recommended this book, which has been incredibly helpful:
The Dialectical Behavior Therapy Skills Workbook. DBT was originally developed to help people with borderline personality disorder. But many found that it was helpful for a whole array of problems, including various forms of anxiety. Like a lot of new approaches, the originators seem to indicate that the approach must be followed rather rigidly step-by-step. But that's not so - I've found that just dipping into the book, taking from it what's useful, and practicing the skills is an excellent aid for dealing with overwhelming emotions, developing distress tolerance, mindfulness, and interpersonal skills. My psychiatrist, who's a very experienced and brilliant guy, said of DBT, "since they can't put it in the water, the next best thing would be to make it required study in schools. It teaches - very effectively - basic emotional survival skills."
Medication: since I have bipolar disorder, I'm on an everyday combination of meds. However, I also use clonazepam (an anti-anxiety med) on an as-needed basis for anxiety. My psychiatrist's advice: "Try not to rely on it too much, since (like all benzodiazepines), it can be quite addictive. On the other hand, there's no point in being a pharmaceutical Calvinist. This is what this shit is there for. Use it if you need to."
One strategy I've found is to always carry a pill in my pocket. Often just the security of knowing it's there if I really need it help calm me down. By doing this, I've reduced my need for actually taking the pill.
It does take work. But hang in there. You're not alone.