Only to discuss from a medical point, the 'partying' caused the atrial fibrillation due to stimulation from those drugs.. Weed will also cause PVC's and other heart abnormalities and hence cause the heart to go off beat and that is where the beta blockers are coming into play to help regulate the heart rhythm, you do know atrial fibrillation can and will kill you eventually if your blood pressure is high, if you do not die you may get lucky and only have a stroke ?
Because you have hit the central nervous system to the degree you have, the damage is done, stopping the coffee was a wise idea..
If this was me, I would stop the test, I would work with bloods and only focus on returning your levels to a normal healthy range.
Don't reminisce on the past, because that image in your head and the way you believe / or really did feel is never going to return, and you will never feel satisfied and get what you looking for. Life changes you get older, your body changes and this includes rejecting things that may have made you feel better.
You went through trauma, the hospitals, the cardiologists, the anxiety... You have re-wired your thinking pattern and also caused a shift in the chemical structure of your brain. You have probably done permanent damage to yourself in ways you not even aware and to other organs (I bet your kidneys have taken a hammering too).
Even from a 'natural' treatment method / alternative treatment, you will never get back your health and feel the way you once have. Years of smoking weed causes severe damage to the brain and neurotransmitters, weed is one of the easiest drugs to cause psychosis (temporary but sometimes permanent (if it's chronic / hydro)). Your mind is extremely complex and the only way you going to start sorting yourself out and helping yourself find balance is to just stop putting stuff in your body. Every medication with a S* on it has a list of side effects.
What you are explaining is an extremely vast in nature and you need to start putting effort and energy into 1 thing at a time. But my initial suggestion is stop putting crap in your body, this includes PCT medication.. Psychological damage and shifting your brains pattern could very well be your reason for you never 'fully' recoverd.
NOTE: Please do not argue (anyone) around the side effects I state that certain 'illegal' substances cause. If this post shifts any further from the use and side effects of anabolic steroids, it will be locked.
"Whether You Think You Can or Can't, You're Right"--Henry Ford