Suggest Treatment For Severe Pain And Pressure In The Chest

Hello, I ve been having really bad chest pains for the past two days now. They re not sharp its like a squeezing, pressure type pain that is causing me to not be able to sleep. I ve gotten looked in the past two for any health problems, I ve had blood tests and ekgs done to rule out any heart problems. Also I m only 20 and I ve been experiencing panic attacks in the past two months but nothing brings them on and I haven t really had them in awhile. The last visit I had to the doctors they said it could be acid reflux so I took zantac once a day for a week then up it to two a day and stopped taking it about a week ago. I felt a lot better, I had no chest pains, I could eat again. But yesterday I had took a hit if my friends MJ blunt but only a small one cause in know certain weeds cause anxiety and then I had some crumbs of a weed brownie as well as frappechino from Starbucks. A few hours later I began to have chest discomfort and aches I even called an ambulance only to send them away because I was hoping the problem would subside but now it s the next day and the aches haven t got been and are worse when I m at home not moving around. Should I take my zantac again and see if its my acid reflux or could it be something else,