There have been several women who got emotional problems when starting birth control, of various forms. This is common. You don't have that problem -- you didn't get this when you started, you got it after 10 years on it. That's why your doctor, probably correctly, reasoned it wasn't that. But your doctor shouldn't have stopped there. There are many reasons for anxiety and sometimes no reason at all, but it's always important to rule out all possible physiological reasons before concluding it's a mental illness without any known biological cause. thyroid problems, blood sugar problems, food allergies, MSG, all kinds of things can cause anxiety and should be investigated by your doctor before throwing Zoloft at you just to get you out of the office (this is what doctors do). And before throwing Zoloft at you, if it is a mental problem, therapy probably should have been recommended first. I don't think it's a terrible idea to stop the birth control and see if maybe your hormones have radically changed and the pill is now affecting you, but it's just very unlikely given how long you've been on it. If there is no physiological cause, and you'd only know by not starting the Zoloft and getting a blood test, a fasting blood sugar test, etc., that would look for all the hard to find causes for this, then know that almost all of us got our chronic anxiety problems out of nowhere. That's not to say we didn't have anxiety problems before, but they were episodic, not chronic every day things. For some, there's some event that triggers it. For others, there is no such event, it just is there seemingly all of a sudden. As for starting an antidepressant, they do cause sedation very often but know that side effects start before effects, which don't kick in until about 4-6 weeks after you start -- but unfortunately, as I say, side effects start right away. Buspar really does nothing for most people, and clinical trials show that, but somehow the drug lingers on -- these days mostly as an adjunct to an antidepressant. I think it's good you start therapy before you go on an antidepressant, but make sure the therapist specializes in the treatment of anxiety. Like other practitioners, therapists tend to focus on certain things and don't know much about other things. And if your therapist doesn't help you, he or she will tell you if your life is so seriously disrupted that medication is needed. At that point, the professional to see is a psychiatrist, not your general doc. Good luck. Have patience. Don't give up looking for the cause.
I don't see the connection you are trying to make with anxiety and birth control. You had anxiety when on and off the pill.
Hopefully the counselor helps, because sometimes anxiety is brought on by things we would never imagine, but a one on one conversation might bring out the cause.