Dizzy and don't feel right...?!

Dizzy and don't feel right...?

I'm 17, 5'4" and bounce between 120 and 140 all the time. I never change how i eat or how much i'm active. I'm fairly active i would believe i'm outside at least 6 hours a day I eat good meals, not a lot of junk food. Lately I've been dizzy and lightheaded. Especially when I get up from sitting or laying down. My neck hurts sometimes and then I get pounding headaches in the back of my head and right above my eyebrows. usually I can close my eyes and breathe for a few minutes and it will pass. I can feel my heart beating really fast, then really slow, then skipping around (they call it heart murmer i think?) then when i sit still my legs hurt and tingle. then sometimes for no reason no matter what i am doing my heart suddenly hurts and it's hard to breathe and my left arm goes numb. it's hard for me to get warm and stay warm. often i have no feeling in my toes or fingers. my mom told me not to worry about it, it will go away. what is wrong with me? what could be the possibilities?

3 days ago
it's summer right now, and average of 85 or 90 degrees, yet i'm still cold.

3 days ago
what is heart murmur? what harm if any does it do?

All your symptoms have happened to me. I'm 17. The only thing with me is that i've NEVER been able to lose weight. last year I ran 8 miles every other day for 4 months and i didnt lose 1 pound.
Trust me, it's nothing to worry about. Most of those things probably have nothing to do with each other, you're just scared.
The thing that sounds weird is that you fluctuate between your weight. Have you tried talking to your doctor?
That is so weird! I get exactly the same things, right down to the heart murmurs and the left arm numbness and the dizziness!Don't worry about it. ;)