Sulfamethoxazole and yesterday morning

I was given this medicine for a UTI on Saturday. Only 6 pills, twice a day. From the 1st day I started feeling very weak, rashes and pain on my body, stomach cramps
nervousness, head aches, loss of appetite, nightmares,
sore throat, sores on my tongue, mood swings. I took the last one yesterday morning and today I still feel very sick and the side effects are just getting worse. I can not believe I wasnt told the side effects of this medicine. I never in my life (30 years) have experienced a reaction like this to ANY medication. I can not belive this was approved to be sold.

I was prescribed Sulfameth for a UTI 6 pills for 3 days. I have allergies to most anibioics, so I was a little nervous taking this medication. I have had non stop nausia for the past 3 days, I took my last pill yesterday morning and I once again have nausia this morning... I have also been suffering from heartburn. The discomfort from the UTI is almost gone, but I have been taking gravol (anti nausiant) as well as tums continually to battle the heartburn....wondering if I should go back to my doctor as I still have slight pain...