You may have the last of the Getrag 5 speeds (MT5). They were decent but had some issues and replacement parts are no longer available.
If you have one of these, unscrew the shift lever, then take the top of the trans off-4 bolts. Check the roll pin where the shifter connects. If that comes out, even part way, the trans becomes VERY difficult to shift. I ended up putting a cut down 20 penny nail into that hole, and it has been working well for 2 years now. Check it out, and maybe you can save your self a bunch of grief.
(The Camaro T5 is not the ideal T5 to use)