Can Increased Heart Rate Indicate Hypochondria?

My resting heart rate is 104 beats per minute and I think that might be a little high:/ i am 14, and not overweight or anything, im quite fit otherwise (as in I get enough excersise lol). Im probably being a bit of a hypochondriac but I have also been sometimes short of breath - I am just sitting down or resting and then suddenly I get the urge to hyperventilate, then it slows down a little but it feels as if I can t fill my lungs with enough air... Whenever I stand up I feel lightheaded and sometimes my sight even goes for a few seconds. I also sometimes feel my heart like when you feel really nervous, only its when i am not nervous at all. So theres all my problems, lol. Its probably nothing (as I like to say on all my questions) but I want to get some peoples opinions before I start complaining to my mum. Thats the other thing. My mum doesnt take anything too seriously about our health because neither me or my siblings have ever been really ill. She kinda has to see it to believe it if you get me:L please just give me your opinion, hopefully theres nothing wrong with me apart from being a hypochondriac:L ok thanks:)