What Are The Side Effects Of Ofloxacin?

hi i have lower left abdominal pain i have had sti check urine check and blood checks all clear,my gp has prescribed doxycycline x2 100g per day and x3 metronidazole per day they have given me headache sick feeling and swollen stomach/bowel area,sfter just 3 days of taking them ,i returned to my gp who had now given me ofloxacin instead ,i am concerned about the severe side effects and that they seem greater than the original drugs given,what should i do?can i just go back to my original drugs ?