I would cut out the beer and maybe nuts. Eat more at breakfast so you don't need to snack. You know the issues with work, sleep etc.
As for the heart issue, I would make an appt with a cardiologist and ask for an echocardiogram. They generally don't do bloodwork, so cholesterol isn't an issue. You want to make sure you don't have a real issue with heart valve etc. Even if they do prescribe something, do your research and decide if you feel it is necessary.