I think it will not be possible for you to get Levothyroxine (Synthroid) without a prescript
ion. By Federal law it is a prescript
ion drug, not allowed to be sold over the counter. If you can scrape up the money for a follow-up with the doctor, the medication is pretty inexpensive. Perhaps your doctor would let you work out a payment plan to make it easier for you to pay?
Please do start planning ahead. You have a chronic condition which will probably require treatment for the rest of your life. Look into insurance through the Affordable Care Act, or consider trying to find a job that includes health insurance in their benefits package.
The long term effects of hypothyroidism can be serious. I'm including a link to information about