Why do I feel so undeserving?

I’m 22 years old and I know marriage for myself is not gonna happen as of now or anytime soon. I do often think of my future and being married but why do I feel like I am undeserving of it, like for someone to love me and be devoted to me? I’ve dated two people (besides the person I am dating now) my first boyfriend was very good to me, we had a healthy relationship. The second one was toxic and traumatic but beneficial at the same time because that relationship taught me what I did NOT want in a relationship. The relationship I’m currently in is healthy very communicative, we both have our cons as everyone isn’t perfect, he loves me and is dedicated to me. I guess I have an insecurity because I feel like he deserves so much more that I can’t give him and there’s gonna be someone else that could do more for him than I. I feel like I deserve to be alone for the rest of my life, and that even though I would love to be married and be able to grow a garden and have kids and be a good wife and love someone dearly I just feel so underserving!! How can I not feel like this or is this an insecurity? I need some clarity