Default Recovery not able to load Rom , phone stuck after start

Hi ,
I have some recovery in my G2 whish doesnt have toggle signature option as a result im not able to flash a new ROM.
Also i edited the buildprob and somethign went wrong so when i turn on the phone i get,systemui has stopped working all the time
so im unable to do any thing.

Please suggest what can be done,
is there a way to flash TWRP so i can install a new ROM