2005 Ford escape 2.3 l with transmission problems I think or brake light problems

I purchase a 2005 Ford escape it ran fine all the lights work transmission run smooth no
problem I ran about 8,000 miles came home park the vehicle no problems at all. back in
it 2 hours later backed up put it in drive and it wanted to hesitate so I check transmission
fluid it was full. back in a vehicle playing Johnny went right in nevergrind secure got
down the road and realized my RPMs go up pretty high turn down the radio and looked
and the transmission was as if it had was not in the vehicle I could shoot shift my gear
shifter into reverse while I was moving forward since then it has progressively got worse
but it's an odd odd situation because I can go for about 10 or 15 seconds are shift real
smooth from drive and drive first and second sometimes third sometimes just first and
second sometimes only first before it just disappears it's like I have no transmission but
I can put it in neutral or Park shut off the key count to 10 turn it back on and it will slide
right back in the job just perfect it doesn't grind I try to check the filter the filters not in
the transmission but I did take the fan off and there isn't the filter I guess is in the wheel
well and I haven't gotten around to finding it I replace a neutral safety switch and I am
presently looking for the PCV valve cuz it's not in the valve cover or anywhere on top of
the engine so now I'm looking under any ideas