I think it's important to spend a bit of time asking yourself if these are genuine doubts about whether university is the right path for you, or whether this is just the natural anxiety you have about making a big lifestyle change. Anxiety can have a way of deflecting from the real concern to try and convince you not to do something - so, "I'm worried about moving away from home and meeting a new group of people" becomes "I'm not sure university is the right path for me".
I say this as someone who was exactly in your position, and I chose to defer after results day. I spent a year working and then took up the place at university, though not without a second wobble nearer the time. My reasoning for deferring was exactly the same as yours - concerns about money and debt, not sure if the course would actually lead me anywhere in life, etc etc. But looking back I was actually just highly anxious about moving away from home, and I was inventing sensible-sounding reasons not to go.
Of course, you may be genuinely unsure if it's right for you, and not in the least bit anxious about moving away. If that's the case, then deferring is a great way to keep your options open, gain work experience, see what kind of career you can have without a degree, and see how much you miss studying your subject. You may find that, if you do go to university later on, your gap year makes you a more attractive job applicant once you graduate because you have a year's more work experience than your friends.
So I really would just take the next week or so to think hard about where you want to go in life, and where this disinclination towards university is really coming from. There is absolutely nothing wrong with deferring, or even outright rejecting your offer, as long as you're doing it for the right reasons and with the right motivation to make it work.