My car has been having issues. Starting, driving, stopping.. code p0717 pops up. Mechanic tried changing the input output speed sensors to tranny. Nothing happened. Seems like it got worse when he

Changed it.. I don't know what to do with
this car anymore. I have a 2005 hyundai
accent Gls 4 door.. automatic t....

About June 2015 my car all of a sudden on
the highway jetted and started revving up to
4-5 rpm when I was going 65-70. It will revv
up past the normal after passing 45 mph.  
It's not going into the last gear. It will stay in
second even after going 50 or 60. Im afraid
to go faster than that because o don't want
my engine blowing.  Now thus new problem
is occuring. When the car is cooled down,
when we start it and put it in reverse to back
out of driveway, it will not go.. it will Rev up
and 3 seconds later it will "pop" backwards
and then when we try going again it will do
the same thing and finally go back. Then we
put it in drive and it does the same thing.  I
park on a hill at qork and when I back into
the space it bangs forward and bangs
backwards when I'm easing in the spot. It's
like the car refuses to go up the hill in
reverse.
Everytime I am in town with air or heat on it
will jerk when I start to go after a stop light
or when im turning it loses its gas power.  
I need help diagnosing this. We've tried
changing many parts. The VSS the
transmission input and output. I'm not sure
if the mechanic put them on wrong and
that's why nothing has gotten better. Or my
tranny is going out! Help diagnose this
please.