PLEASE HELP! Any ideas greatly appreciated!!!
 

Okay to start things off, I was low on fuel so I headed to a gas station when my truck died. So thinking it was a simple fix, I walked to the gas station, got gas and tried to turn it over. Well, it starts right up, but the RPM's drop down to 0 and it dies, unless I keep my foot on the gas. So I drove to my nearby work to try and figure something out (yes it was difficult.), and my oil pressure gauge was showing low so I checked the oil and to my surprise it was almost EMPTY! Well after putting a few quarts in, that did not help. So I hooked my buddy's OBD2 up and it threw 5 codes, 3 exhaust leak codes, a cyl. 4 misfire code which I have known about, and a fuel problem code, so I replaced the fuel filter and put in some fuel injector cleaner, tried cranking it over, dead battery. Jumped the battery again, and it died once again. So I had it tested, and it was bad. After getting a battery from a friend, the result hadn't changed. So I am already $70 in and don't know what else to do..

What engine/trans? I'm assuming it's a 98 like your screenname suggests.

Yeah 98 5.4L v8

Check fuel pressure first, also IAC valve may be starting to go bad.