Fear Of Rejection

I have recently become aware of my fear of being rejected and it’s impacting my relationship and I am having doubts about my relationship. I’m afraid that I won’t be good enough for my boyfriend who says he loves me and who is amazing and who wants to live with me. Do I just observe the thoughts and feel the shame feelings when I notice they come up? How do I not let this sabotage myself and my relationship? Also I think I shouldn’t have doubts about my relationship. Is it normal to have doubts?