Turning engine on Issue

Hey all, 2012 Cascadia DD15 3 filter fuel system 495K here. I've been having some real trouble with getting the engine on every time I turn it off so I've been forced to recently leave it on till I get it fixed. Before anyone says to scrap it and get another one, I own the truck and title, so it either owns me or I'm into deep. Anyhow, it has a NEW fuel pump installed only 5 or 10kmiles ago, but it seems it loses prime or something every time. I've tried priming it using the little joystick looking thing pushing down and over hundreds of times and still it doesn't turn on and i'm forced to use quick start spray. It didn't quite struggle to turn on at first when installed, but over time it has gotten worse and now even after a few seconds if i turn it off it will struggle to get back on and I need a solution quick before I eventually burn out my starter. Has anyone had a similar issue and have any ideas of specific things to check? I'll be sending in to the shop after this hitch, but I have always gotten good advice from the forums to have a plan before sending it in. Thanks.

 

Ten four. Definitely look into that.