Age:20  
Sex: Male  
Race: White  
Weight: 144-148ish

4 Months ago I had a serve potassium deficiency and collapsed and had these weird heart episodes because of it and had to get treated for it. I’ve had routine bloodwork checked out afterwards and my heart checked Atleast 4 months ago and I was fine after I got treated for it but ever since then I’ve felt off.   
This might be a long one, but over the past couple of months I have been to the ER about like 3-4 times because I’ll been feeling like extremely off. Like heavy mental fog and visitations  and weird body feelings, horrible GI issues I even fainted for no reason once. It got very bad and they ran a lot of tests on me like a ct scan of my stomach, a lot of bloodwork etc, and found really nothing, I had a serve vitamin D deficiency of 7 that got treated and also had traces of food poisoning at some point. I also attending outpatient therapy and went on lexapro for a bit and expected to feel better after all of that, but I feel the same actually worse even. People keep telling me it’s mental health related but I just feel so off 24/7, the main thing that scares me is the mental fog. 

A couple of days ago I noticed my heart rate goes kinda crazy when I just stand up like this, idk if this is anxiety but it consistently happens. Idk nobody in my life like believes me it kinda sucks badly. 

Is this something I should be concerned about? 20M