Your franchisor isn't helping out, huh?
What kind of feedback have you gotten from them? Do they have a dedicated franchise success executive? Or a franchisee council to draw experience from?
Your long term strategy is to raise the guest check average for each visit, and increase the frequency of those visits.
Along the way you can look into:
-lowering your cost of customer acquisition
-lowering your cost of fulfillment (food, overhead, labor--I guarantee there's waste now)
-lowering the average time to process an order (eg. in the drivethru, how long from arrival, through ordering, to departure with food? Most strugglers are terrible on this stat).
However, you can only cut so far. Expansion is a far better goal.
What you bought was a system with expectations and controls. Your pricing and costs should be known. If you don't know them, you won't know if you're profitable, and that's something requiring immediate correction if so.
Are you looking at what competitors are doing...or what the top franchisees in your area are doing? Chick-fil-A in my area is doing some awesome things with the drivethru...how they staff it, process orders, increase flow through rate. And there are McDonald's in my area that I know are A listers...those that are mediocre B-level performers...and C-types that have poor standards enforcement, lousy culture, and missing processes. Who's the A-lister near you? I sometimes work with a B who is burning to become an A, and that's fun because I know they'll do the work.