Oh mate, I'm so sorry to hear about your Dad, that really sucks
If it's any consolation, you're not doing anything different to what every other person in the world does when a relationship breaks down. I did it, others on here will have done it too. It does get better, it just takes time. You cannot rush things or make feelings go away, all you can do is focus on the end goal of your own happiness and remember that any contact with her is going to set you back from that. Keeping in that in mind *will* help you stay strong, I promise.