Leaking Trans fluid and drive is sticking.

So I took my truck to the shop to have the
transmission pressure sensor replaced because it
was kicking in to nuetral and code was suggesting
it. The mechanic said the wire harness was twisted
and grounding out. Couple other  little things
nothing bad, he said it looked pretty good.  He fixed
what was wrong. I got my truck back. It felt really
tight as if the breaks were sticky. Drove maybe 20
miles home that day. Left next day drove less than
a mile and it felt even tougher so I went home.
Thinking maybe the breaks were sticking. When I
went to back in to the drive way reverse seemed
smooth and normal. So thinking hey I fixed it put it
back in drive and it did not wanna move. Reversed
still was smooth but drive is locked. Also is pissing
tranny fluid. Mechanic has had it 2 weeks and can't
figure out what is wrong. Any clues what this could
be. So I know which way to dump more money. Ha.
Could it be something with the computer since the
wires were twisted, or do I need a new
transmission ?