Lets not run it, until: You check your oil level (dip stick)
You check Actual Oil Pressure, using a MECHANICAL GAUGE (the best way to check) [installed into the Oil Sending units hole/ port] Then start it up and watch the gauge to Verify if you do have Real Pressure. And your SENDING UNIT OR GAUGE are not bad.
Many times it's just the sender, and they are not real expensive. It's up to YOU, to TEST or Take a chance with a new sender. Regardless which you do, insure the gauge does work correctly.
Even Buying an inexpensive Dash Gauge, the type with the long, plastic tube, will work as a Mechanical Test gauge. Get one you like, you might wanna install it and eliminate the Electric gauge you have now, or sell it to your buddy, after the test. If that's possible!
If you do not get pressure with the mechanical gauge, you may have internal Engine problems (like a bad oil pump, ETC)
As for the "Ticking", It might have been doing that all along, You may just be more in "Tune" with it, now that this problem developed.
If your Oil Pressure checks out good, Substitute a Quart of MARVEL MYSTERY OIL, in place of a Quart of MOTOR OIL, when you perform your next oil change. It will free up dirty, sticking lifters (tappets), and the sound may go away.