racing, pounding pulse, and sometimes light headed

[antigens]

I'm 39 however, in the past couple months, I had issues where my pulse would jump into 140-160 from mild exertion. It's come down some. I'm on cholesterol medication and I stopped taking an SSRI. One or the combination of both actions is helping. I'm also a bit out of shape. Unfortunately, my heart keeps me awake at night with the thumping. I can hear it and feel it in my neck and head randomly throughout the day too. Oh and feel it in my chest whether i'm resting or active. Cardiologist says my hearts in the normal area and doesnt know why i'd have a racing pulse like i did on xmas eve at 2am that made me drive myself to the er. ER said they think i had dehydration. (I should mention i've seen zoloft/lexapro causing abnormal heart rate)

Trying to work out is a bit of a struggle. I was lifting light weight to get back into the rhythm of regular fitness again a couple days ago. small weight (15lb dumbells), lifting and squatting, caused my smart watch to alert me that my pulse was 166. I dont know how accurate it is but thats a bit worrisome. I'm unsure what to do at this point. doctors dont help. They say i dont know why you're having these symptoms. you're overweight so take care of that. So if i lose 15-20 pounds i'll no longer be over weight. ok then

Oh and, When I stand up, I get light headed and wobbly.If i put my fingers on my neck it feels like my heart actually stops or slows so far down that theres huge gaps between beats. Doctors dont know why.
Have had echo of carotids and echo of heart. heart monitor which showed a few atrial runs, but mostly sinus tachycardia. Stress test took me less than 3 minutes to get to the required heart rate of 158 i think it was. I sleep light crap too. Sciatic leg pain. left arm and shoulder is sore a lot. And on top of all that, I have costochondritis. So thats fun.

Working out is hard when i exert myself in the slightest and I can feel and heart my pulse pounding like all hell.

Couple years ago I saw a neurologist for headaches and he said my brain scan looked like a normal brain so he has no idea why the headaches. Again, I'm thinking zoloft (over a year or two, cant remember b/c of the zoloft lol) which i was later switched to lexapro (3 months only.) I quit them. things settled down. Anxiety even minimized by being off of them. lol  

[antigens]

I should add, I dont drink alcohol or caffeine, nor do i smoke or do drugs.

[antigens]

no one has any idea why i get light headed or tipsy whenever i stand up or move around? or why my pulse will be pounding or sometimes rapid but not pounding if i eat any food? my doctor has no ideas and thinks its all anxiety/depression even after i tell her i feel much better off the ssri's she put me on.. .