Remember that you're riding out an emotional wave. It will get easier. One day thinking of her will hurt less. One day you won't think of her. And it'll be a day. Then a week. It'll be fine.
When people say focus on yourself, they mean take time to rebuild. What did you lose of yourself that you want to get back? Did things fall to the wayside? Do you have things that will be mentally and emotionally nourishing to turn to?
Don't be afraid to reflect on the relationship. What did you love about them? What qualities did they have that you want to find in another partner? What qualities were red flags? And how were you as a partner too?
Staying present helps with anxiety, as well as grounding and breathing techniques. Do you have a mindfulness, meditation, or grounding practice?
+ Crying, screaming, etc are all friends. These "ugly" expressions of emotion bring us back to baseline.
Talking about it can help release the energy and connection.
And all of this with all the love in the world. Day by day things get better.