02 duramax fuel issue? Need help.
 

Just purchased a 02 d max been going over everything and changed the fuel filter. I filled it with fuel before putting it on. Fired up no issues. Drove it for about 60-70 miles afterwards. Plugged it in just to have heat in the morning for the kids on the way to school. This morning g it fired up for about 5 sec and died. Crank and no start, primer button will not get hard. I've pumped and pumped, no air comes out the bleeder and no apparent leaks. As a last resort to rule out some things I shot a little starting fluid in the intake and she fired up. I've driven it and it's sat for about a hour and it still starts no problem. I got a filter head seal kit, but what I'm wondering also is I drive like a grandpa aND have never seen my rail gauge over 12-13k just driving. So I got on it and it really only shoots up to 15k as I'm letting off the throttle. Possible relief valve issue, press reg, or pump ? How do I go about this issue without blowing a bunch of money? It's been fine until I changed the filter and it's all tight with no apparent leaks, so I'm hoping it's just a filter issue since the only thing I changed was the filter. What would cause the primer to not get hard other than the filter head? Can a relief valve cause this ? I've always been a cummins guy this is my first d max I'm very mechanical and can do just about anything so I'll understand what your throwing at me.