¿Tensión en el pecho y dificultad para respirar desde hace unos días? No sé qué me pasa

hello I'm Jessica, I'm 16 years old pretty healthy kid but I've been having some problems lately. I have a tight feeling in my chest, breathing feels shallow I guess. I feel like I'm not getting enough air in. 

This is the 2ed time I've had this problem but the first time wasn't as bad as it has been lately. The first time this happened I had the feeling to burp and some tightness in my chest. But lately it's gotten worse. The burping has stopped but the tightness has gotten worse in my chest to the point where it makes it impossible to sleep the breathing isn't as bad tho if I'm distracted it doesn't bother me but when I lay down It gets bad, hard to breath and the tightness gets worse. When I sit up or stand or bend over slightly like over my bed or the counter there's some relief to the tightness. 

Anything helps please, I have school starting soon I need my sleep and normal breathing back!!

Oh and anytime this happens seem to be close to my period? I don't know if it has anything to do with it. 

Mi hija experimenta algo similar y después de leer muchos otros posts tiendo a pensar que está relacionado con la ansiedad. El modo en que respiras puede estar agravándolo. Encontré un vídeo en línea que compartí con mi hija de un psicólogo explicando un método que podría ayudar. Tal vez puedas encontrarlo. Básicamente, puedes estar respirando en el pecho en lugar del vientre. Pon una mano en el pecho y otra en el vientre. El pecho o los hombros no deben subir. Pero el vientre sí. Prueba este ejercicio y, por supuesto, consulta a un médico si continúa.