extreme loss of power please help!!! :'(
 

So when i bought my 01Cummins it was running rough i put a new lift pump in it. ever since the the truck had a really nasty idol. Definitely gettin air in the line. I was only gettin 9 psi of fuel but when i stomped on it it would go to 0 so I stopped driving it and got a air dog system. I put it on and now this truck is absolutly gutless seems like the more i drive it the less power i have. Can anyone tell me what may be happining here? I love this truck a ton but can't afford to keep dumping money into it... Oh it also after I put on the air dog started leaking out of my water seperater valve witch is odd to me that no Cummins store i called in the northwest could find me one so I had to buy a new fuel filter housing. I don't think that would restrict my truck much... It runs fine and starts over normal but no smoke or power. Thank you.