Teen, Have Random Bruising Over Legs, Abscesses On Lower Scalp, Thigh, Difficulty In Walking. Negative Anemia Test. Suggestion?

Hello, my name is Montana I m am sixteen years old and have so many odd things wrong with me. I get random bruising all over my legs and have already been tested for Anemia and the test came back negative so I m curious to why I have all of these random bruises popping up on my legs when I m not even bumping into anything. I also have been getting tons of abscesses on my lower scalp , back, thigh, butt and I m a very clean person. I recently went and saw my doctor and he only saw me for two minutes and treated me for mersa which I had a year ago. I feel very achy most of the time and it hurts to walk. I m sixteen and feel as if I m forty, can you please help?