so you have access to twrp still? if so why not just restore your nandroid backup? if you did not make one then that is your mistake......always do a nandroid backup before doing anything to your phone.
so a couple of things.....there is no such thing as a twrp rom. a custom rom yes, but twrp is a custom recovery. it is a tool that you use to flash custom roms and make nandroid backups, among other things.
if you have recovery you can still flash a custom rom, just make sure that the rom you flash is exactly made for your phone model. flashing a rom not made for your device specifically could brick your phone, so be careful.