Car losing power and idles?

So I drive a used ford escort zx2 4 cylinder. I just hit 120K.
My problem started about a month and half ago. I was washing my engine and water got into the spark plugs. When I tried to start it my car miss fired and was losing a lot of power. So I change the spark plugs, used a cloth to get as much water out, sprayed some w-40, and let it sit in the sun for a few days.
Everything seemed fin!
I was planning a road trip cross state. 400miles. I took my car to my mechanic to see if it could make it. He checked the spark plug pressure by taking one out and putting something in. He said I was losing power but as long as I kept an eye on the engine temperature and didn't push passed 65 I was good.
I made it! However my car is dying. I'm losing a lot of power.
My car dies when I stop. It idles horribly. It shakes really hard and not the good normal shake.
Last week I turned on the ac and my car just stopped. While I was driving. **** gave me a heart attack. I stopped and unplugged the maf plug and notice my car would Idle fine when I did that.
So I've searched on the internet what the problem might be. Someone say IAC is bad others say it could be a bad pvc tube causing a vacuum leak.
So my business is done in this town and I need to make the 400mile road trip back home. I usually made repairs on this car with my uncle but I'm not home. My only option is to go to a mechanic. So I don' want to be cheated. Could you list all the different types of repairs and thecost

Ugh, well water and OBD II systems do not mix well at all. I washed my 02 GMC motor and had to replace the knock sensors, intake manifold gaskets, and purchased a 1/4" drive Inch/Lbs torque wrench ($150 total). Mine didn't lose power, but just had a knock at 50 Mph and/or uphill.

Yours may be similar plus shop labor rates. Hope yours will be as easy fix as mine.

Bad battery and idle control valve.