Loss of libido after break up, now questioning?

Don't worry about it. It's understandable that breaking off such a long and serious relationship would leave you like this. There's no need to question your orientation, just why you're still so affected by this. Try talking it out with someone-- a friend or therapist who will lend you an ear and maybe some advice. Your drive will be back in time. You just need to give yourself time to heal from this.