5th,6th and reverse broke need help..

[jbcobra]

I was on the highway friday and was passing a car in 6th gear and something broke now i dont have 5th,6th or reverse.. can someone tell me what might have happened, is it ok to still drive some? i've already had the trans built once because of 3rd and 4th gear shift key breaking and had all upgraded parts put in so this wouldn't happen again but obviously it did.. Also is this something someone could do on there own at home?

Any help or answers would be greatly appreciated..

Thanks Jason.