I was riding and shifted under load--somehow the front derailleur got stuck in between the teeth of my big chainring, such that I could not spin the crank at all while on the big chainring, but luckily I could still bike if I shifted to the little chainring. Since I was in the middle of a long, speedy ride during which I needed my big chainring, I just moved my clamp-on front derailleur further away from the chainrings (i.e. closer to the saddle).

Searching the forums, I've found a few other people describing a bent or rotated FD, but I don't really understand how to bend my FD back into shape. Can someone walk me through the process? The "arch" of the FD cage appears to match that of the big chainring, but it's offset in a way that just lowering the FD would get the rear edge of the cage caught in the chainring while the front edge would still be ~2cm away from the teeth...to guide the eye, I've also uploaded a picture where I've overlaid circles of the same curvature over the FD cage and the chainring. Before this incident, the cage cleared the large chainring with a uniform spacing of ~2mm between the bottom of the cage and the teeth.

In the attachment topViewFront.jpg, the front of the top of the derailleur cage is warped. Is this part supposed to be flat/smooth? These are 105-5800 front derailleurs, if it matters.

Thanks!