Lyndsey -- I'm assuming you were diagnosed as hypothyroid by a physician and based on that assumption, I will pose this question:
Did your DR explain that determining levels needed to correct your thyroid output can be a little tricky and that he/she may need to monitor you closely to make sure you get just the right amount?
Also, as a person who went nearly 10 years with no health insurance, I completely understand the desire to conserve what funds you have and be a "do-it-your-selfer". However, I don't know how you could accurately determine what meds -- even with a home blood test -- (how would you analyze the blood and if you paid someone to analyze it for you, how much would that cost?) you need and then get your medications reliably with no written, verifiable prescriptions from a licensed physician.
Granted, I haven't attempted to order medication online, so maybe there are ways to get medicines without a prescription which I'm not aware of. I was just diagnosed as being hypothyroid in early April of this year and my DR explained to me that the thyroid provides the "fuel" which runs the "engine" of your entire body. If it doesn't work right, nothing works right. So, it's a sensitive area and I would say to please be careful, whatever you decide to do.
Also -- one more thing
-- have you considered going through your local health department? I did that for several years before I married and was put on my husband's plan and they were very helpful. Might be worth checking into -- to see if they have a program in your state for the medically uninsured.
Good luck to you!!
Let us know how this works out for you!