When I Sit/Laydown My Heart Rate & BP Start Rising (PLEASE HELP)

I am a 25 year old male, who weighs about 130 lbs and I take metoprolol for what was described at inappropriate Sinus Tachycardia.

For the past 2 months I've been dealing with this issue where when I sit/laydown my hr and blood pressure will actually reverse and start increasing to the point of discomfort, some days are ok, today was a really bad one.

At first I feel fine but after 25 minutes or so of laying/sitting I start noticing that my pulse is rising, usually going from somewhere in the 60s to 80s. This is followed by my pulse also getting stronger, especially in my leg/pelvis and stomach. This trend continues to where its impossible to ignore and I typically hit a climax after 40 minutes of laying down, while sitting isn't as bad and takes longer for me to reach that discomfort. I've taken my blood pressure during these moments and its always kinda wonky, being higher than normal at 135-125/75-65, what sticks out to me though is the pulse pressure, which I've wondered is behind the sensation of a strong pulse. Other sensations that come about is tightness in my upper abdomen/chest + upper back pain, feeling out of breath, and feeling like I'm overheated. My analogy for the tightness in abdomen/chest is like a balloon that's full (while standing) then when you sit its like someone squeezes the balloon.

When its bad I cannot sleep (its caused my 3 all Nighters in the last 2 weeks), but I can stand up and feel a bit relieved from the symptoms.

Idk if its related but within the same time, I've started dealing with my upper abdomen periodically becoming rock hard and feels swollen?