I don’t know where this talk of gap years and CC is coming from, the advice you have received is correct.
If you went to a public school, then your academic exposure has been very limited as the NYC public school system is abysmal. Even if you went to one of the “Gossip Girl” schools like I did, your intellectual exposure; while far greater than the average high schooler, is still limited compared to what a school like Swarthmore has to offer.
When I applied to schools, I read the course catalogue for every school I applied to, and even several I considered but chose not to. I don’t recall ever being told to do this but all students should be doing it when applying. I would just read the titles in the departments I didn’t think would interest me (and occasionally I found a class that did) and I would read in detail every course in the departments that did interest me.
In your case, you have only one catalogue to look at: Swarthmore. Go through it. Read about each course they have. Since you don’t know what major you want, look at every department and note the courses that sound interesting. Note which are the ones you could take freshman/sophomore year without pre-reqs and which are the ones that will have to wait because of pre-reqs. Maybe you’ll notice a pattern - a specific department or a theme across departments that keeps popping up in the courses that sound interesting to you. That might be your major. If not, start looking at what is required for various majors and what you thought was a random selection of courses actually fulfills a given major. When you’re on campus, there will be plenty of resources with regards to finding jobs and when you go to a school like Swat, you’re employability is not completely tethered to your major like it is at weaker institutions. At the very least, going through the course catalogue will give you a sense as to what you’re going to take freshman year and who knows, maybe something that you learn in that class will inspire you to learn more.
With regard to everything else. Totally common. You’ll get over it after the first 2-4 weeks on campus.