We can't tell you anything about INS or cost, you need to speak to them.
What about insurance? Will they support or keep it all private? Just wondering how much it cost?
Just make an appointment at your local sexual health clinic, they have to keep your results confidential, the clinic i went to even had the option to send your samples with a number (not a name) so that it could be 100% anonymous.
I worried myself stupid lately but i've learnt that it's best to just go in and get tested (and try not to worry), they are there to help.