I feel you! I know the struggle . I'm also chronically ill since age 7 with no real diagnosis yet. I also have tachycardia, severe fatigue,brain fog, memory issues, shortness of breath, dizziness among other things. I think I might have a relapse of chronic Lymes disease and inappropriate sinus tachycardia but am waiting to see specialists. Have you ever been bitten by a tick?

That sounds like what I was experiencing. I literally felt like I was dying. I kept on going to the ER, and they told me I was having anxiety/panic attacks and BPPV, but my doctor ordered a 48 hour Holter monitor, and it showed that I have SVT. I've been on Toprol XL and Dyazide for a week now, and I feel so much better. I still experience heart thumping and racing at times, but not as bad as before.