I am 14 years old i recently have had some problems of going pee

I am 14 years and about 2 months ago i had some kind of infection that would make me very tired and light headed and a little bit of aches in my lower back where the two main muscles in your back are. I got better for a few weeks then it has come back again and now i have shakiness and fatigue again i basicely have aches in my back and loss of appetite i know it can't be anything to severe because my color is not pale (im white by the way) so i was wondering what it could be it would be great to have a response.