I think i might have anemia?

Some of the symptoms you listed are possible signs of anemia, however a blood test will point the doctor to the answer on that. If you are a little anemia (not a shock for a 15 year old girl) often it is very easily corrected. It can be something more, but it may be as simple as a bit of change in diet or adding some supplements. The coughing for 2 months and producing phlegm shortness of breath etc is probably a second issue, but it could be that your immune system is fighting the effects of one thing, or something is weakening your immune system so these respitory issues are able to get you. Talking to your doctor is the best way to get it fixed. Sometimes it does take more than a few visits, dont get too discouraged yet. Diet, and supplements, are something to talk to them about. Get that immune system every bit of ammo to fix itself.