scared it could be something serious

Hi, I'm a 24 year old female with no health problems until recently except hypothyroidism. Seems like it started after I had my son 8 months ago by c-section. I've got all kinds of things going on including abdominal pain, yeast infections, back pain, thrush, rapid heart rate, chronic diaherra (diarrhea), chest pain, prickling in my body all over, heaches, burning sensations in my face and arms... I go see my gastro guy tomorrow. I've been to the ER 4 times in the past two months and my ob/gyn and GP a least a dozen times. Last night I went to the ER with a racing heart rate probably about 120, which is high for me. And for the past few days I can see my pulse very clearly through my stomach, had back pain, and sore ribs. My heart rate once I calmed down has stayed at around 100. It's been around that for weeks. Well, since I have had 2 cat scans done on my abdomen and  one ultrasound on my pelvis, 2 ekg's, one chest x-ray,  and tons of bloodwork, they sent me home from the ER last night saying that my heart rate was up and was I dehydrated and to follow up with my GP in the morning. I was concerned about an abdominal aortic aneurysm. The ER doc said no not to be concerned because I have had 2 cat scans done it would have shown up. The most recent one was done with contrast a little less than a month ago. She said that aneurysms don't just show up overnight. They are gradual things that grow in size over time. Then my GP said this morning the same thing and not to worry about. However she said she heard a click in my heart, possibly a mitral valve prolapse that she's sending me to a cardologist in a couple of weeks to see. So can y'all help me a bit. I am so afraid that I gonna have something life threatening even though I've been told that it's not and I've had all these tests. Any knowledge would be helpful

[ireneo]

Did the doctor do anything or recommend any treatment for the dehydration? That can cause a multitude of problems. A few weeks ago my Mom spent a night in ER due to dehydration.
What about the hypothyroidism? You didn't mention taking any meds for that. That can cause full body health problems.
I can see my abdomen pulsate with my heart beat. My doc was worried, had an ultrasound done, no problem there. It just burbles along.
Heart murmurs come in different sounds and severity. Most people have some kind of "mild" or "trace" heart murmur but it causes no trouble. I've had one all my life. The doc will monitor it whenever you go in but most likely it will never progress to anything bad.