Hi anh.
Well first and foremost i would be having a full thyroid profile bloodtest, you might have an underactive thyroid which may be the cause of your tiredness.
Underactive thyroid can also cause breathlessness.
If not you need a full blood count test, to check for maybe anaemia, especially being 16 and having menstrations.
Then if thats normal, you may need some cardiac, testing to see why your breathless, and maybe lung function tests to.
Then if them are ok you could check for a underlying virus, like the epstein barr virus.
Dont worry go and see you GP and explain the tiredness, im sure he will want to find the ause for you.
My guess would be its either thyroid related or a little bit of anaemia.
Which can be easily treated.
Good luck.
Keep me posted
Nicola
HI Anh!! It sounds to me you need to see your family doc. You might need some blood work done--check out your thyroid etc---------so, if it continues---which it sounds it is---that is what i would do..........take care. Sunflowers
I support the anemia theory but another thought was could you be over-training? I also felt like that prior to been diagnosed with exercise induced asthma.
My advice would be to talk to your doctor. They will be able to determine what is going on.
You probably arent eating well, if not, then your not getting enough sleep. If its none of this then by any chance are you pregnante? just throwing things out there to hopefully make it easier for you to narrow down the possiblities..God Bless and ill be praying for you :)