My advice to an internet fella, when asked about what to do after a breakup (with the ex trying to reconnect):
Use your head, listen to your gut, and follow your heart. Words I live by.
Listen to your thoughts. That's the sound of your brain coping with things. Let it do it's job and do what you can to stand out of the way. It's going to be ugly, painful, and make you feel helpless. As much as you can, don't get in the way. Trust that in enduring you will survive and grow stronger. Fighting it is exhausting, and ultimately futile.
Trust your instincts. It's harder because you're going to be emotionally conflicted, but surf that until you hit critical and then trust your instincts. Since you have a 50-50 chance at horror or wonder either way, might as well go with your gut.
Follow your heart. I said years ago to a friend, "love hath no patience for a timid heart." Words to live by. Love is a magic beast with painful claws but there is no greater beauty in the world. Be bold with it, as it is with you.