@strangerstranger,
Your English is fine.
First, even though this relationship was between two females, the feelings you are experiencing at the breakup are the same as I've felt (I'm male) when a lady has decided to end an existing relationship. And that's happened a few times. Real healing only comes up after some period of time has passed and some new and rewarding relationship begun. We all suffer this sort of heartbreak and we all, eventually, get over it.
That there's a blow to our self-esteem in such a situation is very common. It has always been part of what hurts for me in these situations. Just be confident that it is temporary.
And I'd suggest that you seek out new means of meeting people and new activities. That's not merely a way to discover new possible partners but also a way of getting your mind out of the patterns you're now going through.