Lara i see my exbf who i loved very much every day at work. at first it was extremely difficult as i could never get away. he seemed fine about it as if the time we spent together meant nothing at all. but with time it gets better. i go with the business talk. im polite to him, but i dont chit chat or have a joke with him like i do with everyone else in my group. i pretty much ignore him. if we are talking work, then im professional. take your time, but time heals all.
as for what has happened, i hope you feel thankful that you got out before that was you in the car beside him. he is the one that must live with what he has done. you need to just let him own it on his own. his problems are not yours. keep going with all the great things you have been doing and getting your life back on track. and leave him to sort out his own problems.
and i hope those poor souls that were hurt by his actions make a full recovery. no one likes it when innocent people get injured by others who show no regard to the safety of themselves or others around them.