Please help: Key won't release from ignition

The other day I woke up and when I put my car into reverse, it was harder to shift from park to reverse than usual (I have an automatic transmission). The car drove fine but it was also harder to put it into drive and back into park. When i went on my next trip (it was still hard to move through PRND) but when I put it into park my key would not be released from the ignition. I had to re-put it into park a few times, slamming it, until it finally released. This doesn't happen everytime, but has happened a few times, but I have always been able to get it out. I am assuming something in my shifter is broke or loose that is preventing it from easily shifting and registering that it is in park to tell the ignition to release my key. I am wondering what part this is and how easy of a fix it is.

Thanks