Tested the pressure at the hose bib,and my water pressure is 110. If the pressure is so high, why do I have such a significant pressure drop when I flush a toilet?

You most likely have bad valves some where or there is a problem in the water differebtial exchange system.

A home with 110 psi would normally have a pressure reducing valve (prv) does you home have one, it could be malfunctioning.

How old is your home and what material are the water pipes? Copper, plastic or galvanized?
Bob's asking about a PRV valve,(see image). This PRV valve will be found where the water enters your home. Do you have such a valve installed?
110 PSI is over twice the average house PSI of 45 PSI. At 110 PSI this puts a strain in fittings and faucets.

why do I have such a significant pressure drop when I flush a toilet? If I had to guess I would guess old galvanized pipes that are choked with rust that's cutting down the volume. You're simply running out of water and with that comes a loss of pressure. Does that sound correct to you? Let me know, Tom