'I Can't Get Over My Ex. I Think Of Her Everyday'

When i travelled to Russia to study medicine I was 23 years when I meet a very beautiful Russian girl named Yulia
She was 17 turning to 18.

I loved this girl with all my heart and she was so in love with me. Infact she loved me too much.
I was her first black boyfriend
We dated for 2 years
Then we broke up because I needed some space.
We still became very close friends after the break up.
Until she got a new boyfriend.
She called me crying and telling me that she has not loved any guy in this life more than me. But she doesn't know what to do about this rich guy who wants her.
I told her to go ahead, that if he can give her the life she always dreamed of living.

She clearly want this guy because of his money. Her new boyfriend is very rich and me I wasn't financially strong then.
Her boyfriend knows I'm her ex, so he forced her to block me everywhere.
We haven't talked since 3 years

I moved on like nothing happened
Now I'm back in Nigeria
It's been 3 years now
But here is the problem
No matter how hard I try to forget her
It doesn't work
I still get flashbacks of our love, romance and all the good times we had.
No matter how hard I try, I just can't forget her.

I got into a new relationship which ended shortly because the girl I was dating said I was still in love with my ex. That I talk about my ex more than I talk about her.
And it's true, I unknowingly bring up my ex in our discussion.
How do I get over my ex of 3 years.
I sometimes cry at night thinking about her
It's so weird, I have never had this kind of bond with a girl.

How can I remove her from my mind
It's like I'm spiritually tied to this girl