Phone thinks speakers are plugged in when they aren't

[TheChaospower]

I'm not sure what caused it, but I suspect my headphone jack may be messed up because whenever I try to plug something into it it seems to go only about 3/4ths of the way through. So whenever I talk, I have to use speaker phone to hear people. Is there any way I can fix this, or at least force it to use the phone speakers?

 

[TheChaospower]

Okay, another weird effect? Somehow, whenever I plug in the headphones it calls the last number I talked to. I think it has something to do with voice commands, but I seriously cannot understand this one.