If you've allowed a "crush" in the past to "nearly kill you" then why are you not asking this man out right now to find out if he's "interested, or just wasting your time?"
If you ask him out on a date and he turns you down then he's not interested.
If you ask him out on a date and he says yes... then he is interested. It will take time and to see if he reciprocates your invitation in what capacity he is interested in you.
Don't let him play with you. Just get the question out of the way and either be happy or be disappointed but able to move away from your crush so this one too, doesn't 'kill' you.
Good luck. Let us know what he says when you invite him to do something date-like with you.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion