Wow, that must have been scary.
You can faint when your heart goes out of rhythm - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5135178/ Did that cause your fainting? Hard to tell.
Afib doesn't always show on an echo. A echo is a brief window into your heart, and it won't catch afib if it's not happening at that time. https://www.webmd.com/heart-disease/atrial-fibrillation/afib-diagnosis#1 With the results of the event monitor and stress test, along with the echo, your cardiologist will have a clearer picture of what is happening.
You could be back in afib with the chest pain that comes and goes, but there are many other things that can cause this. This is something you can talk to your cardiologist about. Maybe keep a diary of when you feel the pain, and see if you can compare it to what the event monitor shows, so you can begin to recognize what is and isn't afib.
Waiting is one of the hardest parts, I think, of being "sick". You know you don't feel well, or "right", but you don't really know why. It's quite frustrating. Hang in there!
Keep a list of questions for your doctor so you don't forget them the next time you meet with him/her.
Hope this helps!
This link explains what paroxysmal afib is - https://www.webmd.com/heart-disease/atrial-fibrillation/paroxysmal-atrial-fibrillation-facts#1
Essentially, once your heartbeat returns to normal after 7 days, you have paroxsymal AFib. This is often a permanent condition. Again, the only way to know is time and waiting (I'm so sorry - there are no easy answers here.)
Definitely get your liver checked out. One of the possible causes for AFib is drinking a lot of alcohol, which can also elevate your liver enzymes. Obviously, I have no idea if you drink a lot or not, or ever. If you do, that's something to talk about with your doctor.
Keep us posted!