My guess is you have a reload stuck in the chamber. It has a swelled case head and jammed up everything. The hard part now is to decide which way to go?
If the slide is VERY close to going into full battery I would hit the slide from the rear and try to force it into battery. Once it goes into full battery you simply pull the trigger and the spent cartridge will eject as normal.
If the slide looks like it has a way to go, do your best to extract it. I use a cross muscle move that is very popular in USPSA. I am right handed so I grasp the slide only in my left hand with the handle of the frame open and facing towards my right hand. I then bring my hands together in a clapping motion striking the frame with the web of my right hand just like I was going to hold it.
The most I have EVER had to hit the frame in this manner is 3x. I guarantee it will dislodge any round or rip the rim from it.