Leaking green fluid-not coolant-shakes at 60+mph

My 2011 Altima Sr with 59,000 and a cvt as well is all
messed up. Bought the car used with 37,000 from the
Nissan dealership. About a month later check engine light
comes on and off over the course of a week so I bring it
in. Turns out I’m misfiring on one of my pistons. They
never fixed it because the check engine light wasn’t on
and they didn’t know the code or what was wrong.
Hmmm... check engine light was off but you were able to
tell me I was misfiring from a piston. Okay. Months pass
check engine light never comes back on even till this day.
Now I have this other problem where I’m leaking green
s#!+ all over the place. I live in central Connecticut and we
just got about a foot of snow. In the snow, were my car
was parked, I noticed a lot of green liquid. Wasn’t my
coolant for that is blue. Or brakes which are a
reddish/brown. And all my other fluid levels are normal.
Car start to shake at 60mph and gets more intense the
faster you go. My car is stock and it is a 2011 niassan
altima Sr, has the 3.5 v6. I think it is a steering stabilizer
but not 100% sure. Any help would be nice.