I have a Nikon fm10 and am having some struggles?

I've come to the end of my film and am ready to take it out, but 1- my film advance lever is stuck. And 2- the back of the camera isn't opening. This has never happened to me before so I'm completely clueless and need help desperately!

Did you rewind the film? Otherwise, you'll open the camera and ruin the entire roll. The film advance lever stops when you've reached the end of the film roll. Forcing it may tear the film out of it's storage canister, and then you'll have a whole 'nother set of problems.

1. Press the indented film release button on the bottom of the camera.
2. Flip over the rewind lever on the right-side knob and turn it until you feel the film "pop" free from the intake reel of the camera.
3. Pull up on the rewind knob (same as above) to release the camera back.
4. Remove film canister and take it in to be processed.