So it sounds like you may have lost 2nd gear. Does your shifter fully go int 2nd, it is just that there is no gear there, or does it feel like your shifter may have popped out of 2nd out/been kicked out?
If your shifter will sit in 2nd, and your car doesn't move, then you most likely have lost 2nd gear. If this is the case it is entirely possible that all the metal that has been floating around in your transmission is now starting to take out other parts.
However, if your shifter is getting kicked out of 2nd, it is possible that there is an issue with your shift rods/forks/interlock plungers, etc.
I would recommend that you have your transmission diagnosed by a specialist, and go from there.
Best of luck.