UTI + sex other problem (more info)

I've had this bothersome UTI for around almost a year now, I've gone to my dr @ times and he's given me medication for it, then it wears off ?? And the times he's not there I've gone to a clinic and they've given me medication that'll last a bit & somehow it comes back!? This itching and burning and going SOO many times. I always put off visiting the Dr...which is bad of me I know >_> but I will next  week see him about this.