This is my situation.   I have had many tests done and have seen several specialists.  Doctors continue to tell me I am just having anxiety and panic attacks.  

About 2 years ago I started getting a strange sensation when I stood up after sitting for long periods of time.   It was like a wave came over me and my head would feel like it was about to pop.  My hearing would could muffled and my heart would RACE.  It only happened occasionally so I didn't think much of it.   Fast-forward to the past 6 months.  It has been happening A LOT.  Everytime I get out of breath it seems to happen.  Walking up stairs.  Walking up small hills.  Mowing my yard.  I'm STRUGGLING.  Constantly lightheaded.   It just won't go away.   It's better when I'm laying down, but I still get hot with waves of it.  I'm terrified of driving distancess, I'm terrified of going to the store,  I'm terrified of just enjoying myself because I think my hesrt is going to start racing.  We are on vacation and I'm letting every moment pass by.  I'm 30 years old and this should not be happening.  

  I've had a head MRI, cervical spine mri, thyroid ultrasound that concluded a 4 cm benign growth on the right side and a t-4 less than 1 cm growth on the left side.  (Suggested follow up ultrasound in 1 year)  labs out the ass, I'm 6'1" 330 pounds.  I was 375 about 6 months ago but have been slowly losing weight while this is all happening.  

They want me to take zoloft.  I tried welbutrin and lexapro.  Both made me feel TERRIBLE.  The lexapro gave me zings down my arms and totally deperosnalized. 

Someone reassure me I'm not fucking dying and I just need to start the zoloft.   It's been gradual but feels like it came on so suddenly.