lol hi I’m new to actually trying to get a grip on my psyche so please bear with me

I’m a man in his mid-twenties who has gone through some nonsense. I’ve historically been able to brush off and move past intense family dysfunction, poverty, weird friendship dynamics, stress from extracurriculars and university, anxiety about the world and my future in the tech industry, and came through getting furloughed from my first gig out of college relatively unscathed. I’m finally settling back into work which on paper isn’t too far off from my interests, I’ve finally become financially stable, and I recently ended a long-term relationship that had become mutually platonic in a pretty gentle way.

Seemingly out of the blue I’ve started waking up at night with sensations of intense dread, my heart rate sometimes spiking and there being very little I can seemingly do to affect it. A few weeks back I was sent to the ER after a heart rate of ~160bpm at rest for 40 minutes. Doctors don’t believe there’s anything physiologically wrong, but ever since I’ve had weird, off-feeling sensations where I know I won’t be able to relax. If I keep busy I’m fine, but this has absolutely been wrecking my sleep. Exercise has helped to some degree, but like, what the hell brain?

Taking any and all advice, I’m a generally anxious and stressy person but this is completely new to me. Talking myself down from these types of situations doesn’t seem to work, what do I do?

edit: ty for all the responses and for letting me thought-dump for y’all, it’s actually been nice to just write this all down as well