I tightened the packing nut from behind the shut off valve to fix that leaking issue... now the sprayer line is leaking from either from the nut or the collar that sits just below the nut.. I cannot tighten or loosen it to remove it. There is no space in there for a wrench to maneuver

Use a basin wrench. This application is the purpose of its design. Available at any hardware/plumbing store.

Here are pictures of the basin wrench mentioned by Bones...

Use this tool and you should be all set... sold at all home improvement stores... ;)

MARK