gears?

[winnipegcamaro]

hello, well i was driving one day and my hands were full, i was on the highway and i asked my gf to shift from 4th into 5th, as she was trying i noticed a struggle for her to get it out of 4th(she has to use both hands). didnt think anything of it, about a half hour later was driving in the city and all of a sudden it was stuck in 4th gear, i couldnt pull it out clutch in and everything, i pretty much pushed as hard as i could with no luck. ended up pulling to the side of the road and turned the car off. while off i tried to pull it out with the clutch in and tried it out. no luck. turned car back on and tried nothing. did this multiple times and eventually pulled pretty damn hard and got it out. so now the problem. everytime i shift into 3rd and 4th it grinds. have no idea what is ahppening and i have been driving like this for a bit. i dont want to damage anything further but im guessing this is going to cost some money. anyone have any ideas why its grinding?
thx for the help and support