How do I assure my gf she's not a replacement?

I love my girlfriend so much, but because of past issues and my past, she thinks I'm using her for ***, money, or to get over my past. I just wish she could somehow understand that she's not a replacement of a temp. She's real. And I wish she knew that I'm all hers. And she doesn't trust me like at all.How do I assure my gf she's not a replacement?Prove it to her by the way you treat her, and it takes time.