How can one cope with the fear of abandonment and the cycle of self sabotaging,, I'm dating someone and I don't know if the person really loves me because she is just in another league and she's so pretty, like I get insecure that she'll end up leaving me, and it's really affecting how I am towards the person
Hang in there until she gives you a good enough reason to doubt or leave her. There must be something causing you to feel the way you are and there is nothing wrong with that. Find out what it is, deal with it. Then, again your instincts could be right, it's a tough balancing act. Either way, don't rush into anything until you have very concrete evidence supporting either scenarios.
Bro, you are the catch here. I don't know how to explain this to you that you will understand. But whatever you do, don't chase