i need help figuring out what is wrong with my car

my bronco has slowly be running worse and worse the first thing i noticed was fluctuating rpms while driving and as it got worse it gets hard to start when its hot and humid it doesn't have much trouble starting when cold and also while i drive its hard to get going when i give little gas but if i out it full trottle it will slug then take off. to me it seems that it just hardly get gas im just having troble narrowing it down. i can tell you that i changed a fuel filter and it was nasty had stuff in it the first drive after i changed that it ran normal for a short while i can also say that i change the plugs plug wires and the distributor