Internal hemmoroids. Help and advise.

I have burning sensation in anus and frequent urination for quite a long time more than 3 months. Initially went to GP while i had 8 kg weight loss, doctor suspexted sugar, thyroid,uti  or any problem in stomach. He did all the test blood, Urine culture, Hb1ac, Ultra sound abdomen scan. All things came normal Except ECOli infection which he prescribed anti biotics. He said weight reduction may be due to stress and he asked me to monitor weight. Weight is stable after that. However my rectal burning and frequent urination did not go away. Intensifies if sitting for a long time. I went back again to him, he did DRE and proctoscopy then he said there are pimples inside and looks like internal hemmoroids and he suggested some tablets dezoflav and proctonil for 1 month. But i did not see improvement. Still anus burning and frequent urination is there. I am worried a lot and scared of some kind of cancer. Plz help and advise.