What Causes Sudden Pain In Neck,chest And Headache?

I am 31 female who has lost 65lbs in the past 6 months. No medical history, I eat a healthy diet, and exercise several times a week. Over the last week I have had intense pain in what feels like a vein on the left side of my neck and another point on the left side of my chest. This pain is always paired with a headache that I can not alleviate with pain reliever and lasts for HOURS. Holding pressure down on the vein in my neck does make the pain and pressure temporarily feel better, but it is instantly back the moment pressure is removed. Is this something that will go away or is it something that will naturally go away, or do I need to have checked out?