I had uti my dr said it was a uti cause by staphylococcus epidermis which he said is a bacteria and not cause by sti. i read somewhere that staph epidermis is found weak immune system inividuals and hospital patients. did my dr misdiagnosed me?

Not particularly: Staph epidermidis is a common strain of casual friendly bacteria that are usually found on anyone's skin. It is considered part of the natural "biome" or background germs we all have occasionally on our bodies. They are frequently found as contaminants in urine specimens. It may also be found at the penile outlet & be irritating.