Help me, please!?

Here's the deal: I'm 16, I hold Hashimoto's Thyroiditis (with risks of diabetes and heart attacks/failure), a weak immune system, Iron Diffiency Amenia, there's cancer within my family and there's a randomness that I have some right immediately. Lots of stuff, right? Well, get this: concluding night, I'm lay in bed...and I'm pretty much suffocating. I sit up and then I could breathe again. So I laid support down and then I started have trouble breathing again...then my heartbeat be so slow that I couldn't feel it. I feel around on my body for a pulse but I guess it was only just so slow that I didn't feel it. There be this dull empty emotion I had inside. And after everything started to get dim (blacking out), and I expected an angel to show up and let me know that I have died (no joke). I was crying and praying that I'd be capable of live to tell my loved ones that I love them, and I be spared and am obviously alive right immediately, but I almost died last hours of darkness! What happened? What's wrong?!?!? Help me please!! Sounds close to a full blown anxiety attack to me but call your Doctor !
See a doctor.