Why is my chlamydia not going away?

[carrot14]

About two months ago I had unprotected sex. I noticed that this person had oral thrush but thought nothing of it. A few weeks later my stomach started growling, diarrhoea, whole body itching/tingling, didnt get my period, cold like symptoms and swollen lymph nodes. I got tested but it was negative. Two more weeks pasted and the following symptoms also appeared alongside the ones I mentioned before: genital and facial sores, headaches, whole body/joint pain, fatigue and my period hasn't been here for two months now. I got tested again (blood and swap from the genital sore) and it only came back positive for chlamydia. She gave me the one off pills (two) and the symptoms seemingly went away for about four days and then returned. She gave me the same pills and a seven treatment. I'm on my fourth day now and the tingling/whole body itching has returned, oral thrush is back, diarrhoea and the constant stomach growling. Also this is my first std.

My question is, is it normal for chlamydia to be this hard to treat? Is it possible that I may have had more STDs along with chlamydia? Did I get misdiagnosed and what should I do now?