little help before I spend some money?

Im more than sure I have some form of rod knock, I have it down to one cylinder. It all started coming home from a long trip where my bank1 o2 sensor decided to give me problems it was late so I couldn't stop just need to get home, The next day I noticed low oil and check the oil finding it to be almost bone dry (im guessing double gaskets on the oil filter, just had it changed weeks before) and it was leaking. Oil pressure gauge was out of control. Same time the knock or ping started. I filled the oil back up and the knocking reduced.. now its only on start up and under have load, WOT or around 2800-3200 rpms'

I pulled the plugs praying it was some form of spark knock because the motorcraft plugs are only 3 weeks old. One side looked great, the other side black and looked ashy, the weird part to me is the side that looked good is the side i have narrowed the knock down to. It not an exuast leak, just had it looked at today. EGR is new, PCV is new.

The knocking is a slight tapping when it starts up, but when Im climbing rpms its more of a hammer hitting the engine.

is there anything else I can do before I need to take it and have someone tear her apart and look into the problem? mind you it will be a few days when I get paid (just blew some of it on my exuast)

Im going to college here in texas, and i live over 100 miles away from my home, were I can get the mech i alway use to check the car out for cheap. how much of a job is it to replace bearings.. I have plenty of tools and plenty of help from auto mechanic students to tear it down in this apartment complex if i must.

well the spark plugs didnt have any flakes on them. I took it in today and he did a compression test and narrowed it down to one cylinder, waste of money actually because it was the same one I expected it to be.. He told me last week he had a mustang come in with the same problem and it turned out to be a bent rod, from the sound of mine its the same thing. Said its not loud enough to make any extended damage as long as I get it fixed soon. And as long as a I dont romp on it, or dont drive it at all.

Here is my question.. Me being in College I do not really have money to replace all the rods, since its just one rod, can I replace just that rod? I know that may sound stupid because it im already there just replace them all but it being around christmas, and right before im about to spend money for classes next semester, I do not have money to throw around.

and that 30 bucks was all I had! lol i blew it.