Red pill symptoms and conditions

I have been taking SMZ/TMP since Monday evening for a UTI. I was also given some kind of red pill... I can't remember what is was called, made me sick to my stomach. I threw it away.

The SMZ/TMP is giving me the shakes, headache/neck pain, and body weakness. I have stairs in my house and walking downstairs has become increasingly difficult, even typing this is difficult as my shoulders, arms and hands are jittery, I am correcting a lot of typos.
I rarely take medications for anything... Except this time, I couldn't get away without it, the UTI was too painful. I only have a day and a half of dose left. I believe I will finish it, but it will definitely go on my list of medications that I can't take. I just hope it gets rid of this infection. This is the first UTI I have had since 1990. For the first one I just took some kind of amoxicillin. I don't remember feeling anything unusual when I took that particular medication.
Thanks

Has anyone experienced bilateral achilles tendon tears on Levaquin therapy?