P0087 code

My girl has a 2013 that has been sounding pretty bad lately. Running really good. But sounding bad. My thoughts were timing issues so I took off the valve cover to take a look at things. Sure enough, her timing chain is loose 😔... But once I put the cover back on it runs like shit. Hard to start, no power and you have to accelerate very slowly or it will go into a limp mode. Check engine light has come on saying low fuel pressure. P0087. I bled the HPFP for air a good amount... What could I have done?? I didn't change anything. The tappet under the pump is in place but ticking now when it wasn't before.. what could be wrong????