Transmission Problem???

Key can't come out of ignition, hit gear shift now it it struggles to go into reverse and when I put it into drive it can only go up to 40 mph. Is it the transmission??

First need to fix the ignition. My problem was I cannot turn the key. Key cylinder was replaced and that fixed the problem.
If second problem persists, it could be a solenoid issue. My problem was once it hits around 40, it goes down to lower gear. As a workaround, I told my wife to put it on 2 but that fastest that she can go is 50. Good enough for highway. The solenoid is an easy fix. If you've done transmission fluid, I believe you could also replace the solenoid.