subaru forester 2005. misfire, flashing check engine light.

I have a 2005 subaru forester. I've had the common problem of the check
engine light solid and blinking cruise control going on for a few months now.
As car has been running fine, i didn't look into it. Last week i was driving and
the car suddenly lost power and started to misfire. RPMs shot up, some
shaking, and blinking check engine light. I pulled over and found oil in my
spark plugs. i changed plugs, drove 10 miles home and parked it (havent
driven it since). I changed the valve cover gasket and the cylinder gaskets,
cleaned out cylinders as best i could, still had the same misfire and blinking
check engine light. i did a full tune up (including changing coil pack), and still
have the same problem. before this, ive been losing coolant due to a leak in
my radiator i think. i can see coolant collecting underneith it where theres a bit
of a pan. also i have an oil leak (I believe), thats been leaking small amounts of
oil onto the top of my engine (unknown source). I dont think its the head
gasket because the car never overheats, and my daily commute is up a bumpy
dirt road. and the coolant doesnt have any oil in it. from what i've read a bad
catalytic converter can get way worse from a check engine light blinking
misfire. but it doesnt cause a misfire does it? i know i need to buy a code
reader to get some answers, and will do that in the next couple days, so
maybe this post is preemptive but i'm at a loss so i thought i'd see if anyone
had any ideas. I super appreciate it. I'm not much of a mechanic, but i'm
always trying to learn more every time something breaks. any input would be
appreciated. thanks!