Chest And Rib Cage Pain, Discomfort In Shoulder Blade, Losing Circulation In Arm, Palpitations, Foul Taste In Mouth. Worried

Question: BACKGROUND: I am 20 years old. To start, I am tired ALL the time. I feel like I have been tired for years. Because of how tired I feel, I have very little motivation. I find it hard to do, even the most simple task around the house. I feel as though I always have a head ache. Whenever I stand or walk around for a good period of time, my ankles and wrists swell (especially my wrists). I have been suffering from infertility since I was 18 yrs old (no one can find anything wrong with me). I have had episodes of stomach pains (been to the ER several times over it), but no one takes me seriously and no one has been able to find anything wrong.

LATELY: I have been experiencing sharp pains in my chest (left side) and left rib cage (maybe a pain in my left boob? even an itchy feeling). I also might be feeling some discomfort in my shoulder blade... I also feel like I have been losing circulation in my left arm (almost like my wrist is cramping up)? I believe about a week ago I had a panic attack. I think I stressed myself out over the chest pains, and I kept waking up that night in a jolt (as if someone was startling me awake); also, I felt (that night) as if my chest was being compressed (but I believe that is a common symptom of a panic attack). I've been having these chest pain on and off since then (practically every day, several times a day). I also (on rare occasions) have been experiencing some heart palpations?

Also, I have no idea if this has to do with anything, but I have also been experiencing a foul taste in my mouth (all the time.. no matter what I eat or drink). There have been times, where If I stand up to quickly I become light-headed. Im mostly worried about the chest pains.

I am so scared that I will fall asleep one of these nights and my heart will just stop.. Please help? Please give me an idea of what might be wrong. I am so tired of going to the E.R. I am so tired of seeing doctors because of my stomach pains and infertility... I just want someone to take me seriously. I have been worried in the past, but I have NEVER ONCE feared for my life, as I do now.
XXXXXXX