Personally, I find winged eyeliner more of a sexier look~ not thick, but thin. Dying your hair is a good option, ombre is really beautiful, you could do that. But then again, you don't need to make him jealous, he's already out of your life. Because when girls change their looks for a guy, personalities change through time and words will probably be said. Maybe just find someone better, someone with not just good looks, but someone with a great personality, because you don't want to end up in the same situation do you?
You don't need to make him jealous. Anyone worth YOUR time will be there for you, not flirt with other girls. Don't waste any energy on him. Go and treat yourself so YOU feel better for YOU, not a guy. (Never a guy!) I would do a pretty ombre or highlights now that spring is here. And try maybe a subtle winged liner or just a deep liner color tightlined that you can smudge a bit. Lots of mascara and a nude lip....hot. Good luck! :)