I hope someone can help me here. I have been for the last week experiencing accelerating heart beats. It happens all of a sudden while I am doing something or just lying down. At night, it wakes me up and during the day I experience a bit of dizziness, my arms go slightly numb (both of them) and my throat becomes blocked, hard to swallow. I start breathing quickly and shallowly. It happens at least 4-5 times during the day and 2-3 times during the night. 

There is also a slight chest pain in the middle of my chest and on my heart side. It feels like a needle deep within my chest, or if it's in the middle part it feels like tightness. 

The numbness in my arm starts from my shoulder blades and all the way down to my pinky finger. But once my heart goes back to normal, it ceases, though my throats continues to hurt. 

24/7 my fingers are shaky and my hands are constantly trembling though not in a way that's obvious but I can feel them, though can't see them tremble. I have been thinking it must be panic attacks because of my recent loss of my fiancé due to a really traumatic accident. 

Could it be that or is it something else? I have no history of heart problems and I am only 29 years old.