I'm sorry.
They are miserable, but you are not alone.
I have a list of heart issues and including benign palpitations. They are very scary. I've never talked to my cardio(s) about if they are PACs or PVCs, although treatment is pretty much the same as long as there is no underlying issue. Treatment does sometimes equal doing nothing. However, that should not be the case if they are affecting your quality of life!
Obviously caffeine will only make this worse. Lack of sleep will too (which is sounds like you can't really control right now). Stress also can cause more problems.
I'm very confused as to why they refuse to give you a beta blocker or calcium channel blocker. This would be my first suggestion - have a talk with the cardio about WHY you can't take them. And then if they still no, talk to at least one other cardio about WHY you can't take them. Sometimes they steer clear of beta blockers if there are also respiratory issues to consider. There are still options though.
I've taken diltiazem (Cardiazem, Cardia) for about four years for several reasons. It absolutely does help control the palpitations. About three months ago I started getting the PVCs/PACs to more of an extent again. My dose was upped to try and fix that and a couple other things. It was during a time of extreme stress.
For some I guess it is more noticeable on drugs. I think that is probably the exception and not the rule. I'd get to the bottom or why you can't try something.
It does feel like..omg I don't wanna die! - THUMP. Completely draining. And there is no way you can jsut not stress about them.
I'm linking to a webinar that might interest you. It is mostly about a-fib, which obviously this is not, but there is a bit about benign palpitations. It might reassure you that you're definitely not the only one (the speaker is a very respected cardio here in Michigan).
https://beaumonthospitals.webex.com/...b&format=short