I’m so confused and hurt

My fiancé and I met in October of 2014. We fell in love with each other and moved in together about 10 months later. We had always openly discussed marriage. We have both been married before and we each have one child from our previous relationships. They are 13 and 15. We get his son, my bonus kiddo, every other weekend, and basically whenever we can on top of that, and my Daughter, is with us full time.

Long story short, he proposed to me in 2018 after several discussions about us getting married, and he completely blindsided me after that. He’s always told me that he wanted to marry me and that he can’t bear the thought of not being with me. We have not gotten married, and we have agreed to several dates to which he backs out on. We will be together for 10 years in November. We talked in March and set a date for October of this year. He made it seem like he was all up for it. He talked about who he wanted to invite, what he would wear, etc., I designed our wedding invitations (25 people), I put a deposit down for an officiant, and bought my wedding gown. He’s now asking why we need to get married to prove our love to one another. I don’t think marriage is everything, but it’s been 10 years and I’m so fucking devastated. He keeps telling me he wants to marry me but then says something like this to me? I even mentioned a commitment ceremony minus the legal aspects, to no avail.

I had to go for a drive because I needed some alone time to process everything and he won’t stop calling me. I’m just so hurt and confused.