Chronic Venous Insufficiency and Tachycardia

Hi, everyone! [Long post, please stay and read...]

I was diagnosed with CVT in my legs (all four veins) and had an ablation last year to resolve it. The doctor confirmed, the surgery was a success. I asked him if the CVT could impact my heart at all? He said he didn't think so. Well, I also have suffered from a high heart rate since I was a kid, and I was at my thinnest then. Anyway, my mom had rheumatic fever, and when she was hospitalized, they discovered she also had a heart murmur. My sister also had a heart murmur when she was a newborn. I've been pregnant twice - one with an unknown congenital heart defect, and another with Hypoplastic left heart syndrome.

I am constantly dizzy, especially when I get up from a sitting, crouching, or laying down position. It feels like the world is spinning, and my HR increases from 65 to 111 (most recent reading). And any cardio or activity that would raise my HR, it skyrockets through the roof (160-180 sometimes higher). I also become very nauseous, and I will throw up sometimes.

I've been to a cardiologist in the past, and I was told I had anxiety, and to lose 10lbs. I've also been to the ER, they did an EKG, and told me I was having a panic attack.

But this has been through childhood, I had no reason to have panic attacks that young, my heart literally feels like it's going to beat out of my chest. I've woken up with a high HR and my bed felt like it was vibrating because of how fast and hard it was beating.

I have a cardiologist appointment on the 14th, but I've been gaslit so many times by doctors, I'm just looking for some answers so I can go in prepared. I feel like it does align with POTS to some degree, but it seems to be a popular condition on TikTok, and I know there's a lot of exaggeration and misinformation there.

Sorry for the long post and thank you for any help!