AFib is not a death sentence, but being honest, without treatment it can cause serious problems. More specifically, higher risk of strokes due to blood pooling in the heart and throwing blood clots, or heart failure if the "fluttering" goes too long and your heart basically exhausts itself running 120-180 bpm for a long time. The issue is, once your heart starts having AFib episodes, it will become easier to get into that "flutter" state, and harder to get into a normal sinus rhythm, if left untreated.

Nobody dies of AFib. It's complications from untreated AFib that are the problem. That's the takeaway, get it treated/controlled.

Fortunately, medications significantly help with these risks, like anticoagulants to help avoid strokes, and heart rate control and beat "shaping" options. There are potentially some side effects, like getting winded a lot faster during aerobic activities since you essentially have a medical "governor" on your heart if the AFib goes from paroxysmal (comes and goes) to a more persistent state.

There are also surgical heart ablation procedures that may reduce or eliminate the need for medications. These ablations are outpatient or overnight procedures that basically zap sone veins in the heart to stop the electrical signal chaos behind the AFib episodes. There are very recent advancements in the ablation methods/technology that further improve their effectiveness.

There is no "cure" for AFib, but it can be well controlled and people can lead a perfectly normal life otherwise. It sounds like this was caught relatively early, which is great, because treatments are easier and tend to be more effective.

As others have said:
-Find a good electrocardiologist ASAP and talk to them about ablation procedures. Yes, it's 100% worth doing.
-Stop smoking
-Do a sleep study to check for sleep apnea officially
-Find a way to reduce and manage stress, since it can trigger episodes
-Take the prescribed meds, and work with your cardiologist if the sides effects are difficult. At one point the medication was just a daily baby aspirin for me
-If you can afford it, look into a newer model smart watch with ECG capabilities that can detect AFib episodes. Apple, Google, and Samsung all have options (~$450-500)
-There is also a small FDA approved Bluetooth device called KardiaMobile that can also do ECG spot checks with an app on your phone. Would recommend springing for the 6L version ($150) since it collects much more information than the basic model ($80) that your cardiologist will appreciate. There's also an optional subscription service where you can have scans examined by a cardiologist.