How do you move on from an abusive relationship?

In my opinion, and that's all it is, an opinion, although I have experience with this...

You have to forgive the abuser and forget them. As long as they are still the cause of why you behave the way you behave, you remain a victim - and you don't have to.

Once you understand they are no longer relevant to you in any way - any more than a childhood illness you had, like the chicken pox...it's easy, like walking out of the shadows into sunlight.

But you have to do that before you can love or let yourself be loved. Sometimes that takes longer than a few months.

When it comes to fear, the only way is to face it. The fear is just gonna be there. You have to become more courageous by confronting those things you fear, incrementally if need be, slowly getting used to it again.

For those other questions. Learning to be patient with yourself. One decent way is to think "I'm going to treat myself as if I'm someone I care about." Imagine yourself as someone else. It's kinda a great reflection on humanity, in this sense, because we often neglect ourselves more than we would other people. So, thinking of treating yourself like you would treat someone else can be effective.

How to allow someone to love you will prolly come as you become more courageous by getting used to facing the fear.

Take time before getting involved with anyone. After a relationship like that it's imperative that you learn who you are again, and that takes time and work. Eventually you'll begin to move on without really noticing the gradual change.

Learn about how they operate and manipulate. It's easier to forgive yourself when you see how they play. This book is an excellent reference.
https://www.escapeabuse.com/npd.pdf

You’re not with your boyfriend that had cancer anymore?

Allow yourself time. It's the only thing that will work.

Heal first. Worry about everything else later.

If I get abused then I won't care. Life is Life been there

Time heals most wounds ,,
you're young ,you will live and love again

Get a psychologist and talk it through

You don't... you just move on.

One day at a time

only you can answer that. The fact you think you deserve to be loved means you're not hurt enough to be broken. You'll heal.