Weirdly it may actually help you find some closure. Feel the pain and give yourself a few days to settle down. You will be ok keep working and keep your longterm goal in mind - healthy loving relationship. This short term pain will pass. Remind yourself often that toxic is no good and not sustainable. Hang in there.
It's just so hard because my mind keeps erasing all the bad memories or all the hurtful things he's done. All I remember when I think of him is how sweet he was to me, how thoughtful and kind. How he made me feel so so loved and special. It's harder and harder for me to call upon the bad moments, because they are fading so quickly. I really don't understand why and how.