Chest pains need help and advice worried about heart attack

For the last month or two I've had this tightness in the left side of my chest it's not painful it's more like a tightness feeling accompanied with shortness of breath, the chest pains travel to my arm and back, I can feel it in my shoulder too.

Sometimes it's only in my chest other times it's only in my shoulder or only in my back around the shoulder blade but it's always there 24/7.

The cause could be anxiety or a heart problem, can anxiety cause these symptoms constantly? They never go away not even for a few minutes.

My girlfriend has these sleeping tablets which I take one or two of them every so often, the first time I took the tablets the chest pain went away completely for a few hours and I've taken them a few times after this and the same thing happens every time my chest pain goes away completely and my shortness of breath nearly goes away.

Does that mean my symptoms are almost certainly down to anxiety?