I'm 18M, I've never dated and this has been affecting me in some way

Since December of last year my mind has created an imaginary girlfriend and I nicknamed her Bianca

Her style is e-girl

When I'm alone with no one around I start talking to her about my tastes, family and desires in life

When it's time to sleep I imagine her lying next to me in bed and there are times when I squirm in bed as if I had sex with her

Is this normal or do I need psychologist?