Synthroid doesn't help anymore?

I am 19 and have been taking synthroid for almost a year. My regular doctor prescribed me synthroid 50 mcg to take everyday because I didn't have insurance to see an endo at the moment. I did get my thyroid checked(tsh) when needed, but she never changed the dosage. Now after almost a year taking it, I still feel bad. I have tingling in my legs, arms, ankles, muscle spasms, headaches almost everyday and the most vivid dreams mostly every night(they seem so real) and no periods(i never had regular periods anyways). I also sometimes experience anxiety. I finally have the chance to go to an endocrinologist and will be going soon. Why isn't the synthroid helping? Last time my TSH was checked it was 2.7.