I was diagnosed with costochondritis in July and since then, have had a pain and buzzing feeling in my chest with a weird pain in my left arm on only an inch of my upper arm and lower arm. As of yesterday, the buzzing has gone down and no pain but today ive been feeling lightheaded, which occurred on and off with this costochondritis, but today it started at 130ish and I still have it but I'm not sure if it's because I haven't slept well the past 3 days or I'm freaking myself out thinking im going to have a heart attack (the left side of my neck twitched when I laid down but only for a couple of seconds). Should I get a 3rd opinion? I went to the ER first in July thinking I was having a heart attack but they said it was chest pain the my doctor said it was costochondritis I'm just worried