these 2.7 engines have a TERRIBLE history of “oil sludge buildup”
this problem is often fatal and irreversible, causing damage and failure.
have the engine checked out ASAP. you may need help from a good mechanic to clean out the pan.
is the check engine light on? any codes?
i sounds like you have a failing/failed oil pump.
take it to a mechanic. (not diffylbe, or poopboys) and it can have an oil pressure test done and get correctly diagnosed.
who was the mechanic, a local shop, or a friend? and who else (“someone”) said the timing chain was related to the oil pressure? i would be surprised that the timing chain was related to anything else but the timing and waterpump.