anxiety or stress?

lately I have been having a sharp pain in my chest. it's not unbearable it's tolerable but it hurts. I thought it was that gum that I accidentally swallowed 4 months ago because it keep coming back. I thought it was like a new period symptom but I'm not on my period and its back. today I have been really stressed and anxious. on my periods I'm the same anxiety and stress first few days of them. I don't think they are heart attacks. maybe anxiety attack? any ideas? when I lie down it's so painful I have to move like a sloth to lay down. deep breaths bugs it. when k move my arms to fast it hurts it. I can't bring my arms above my chest without hurting myself. it's on my left side normally or in the middle as shown on this diagram.

I'm 19 years old pretty healthy.