It sounds like you have a problem with spark or fuel. I can’t offer any real advice without having hands on the car.
The alternator would be low on my list.
Who all has had a hands on look? Has a professional had a chance to check it? What exactly did they say?
How often do you drive this car?
When you say
I suggest you find a local independent (that is not a chain like the quick oil change places) check it.