I definitely have a fear of rejection and abandonment too. Avoidant Personality Disorder, etc.
Sorry about what your dad said. My mother had said some pretty cruel things to me too. God rest her soul.
You'll get through this one way or another.
We all will.
I've found someone who I'm almost 100% positive could never reject me, nor I her.
We've been communicating for over two and a half years now.
Buying a train ticket this Friday from Louisiana to Pennsylvania to go meet her for the first time.
I can be very good with online communication.
Taking meds now I hope will help.
But I fear I will be very withdrawn, quiet and nervous around her.
That's ruined many relationships for me in the past.

Social anxiety that doesn't diminish with familiarity is one of my main problems.

Wish me luck.
I wish the best for you.