Helllppp

So me and my boyfriend have been together for 5 years and we have 2 beautiful kids together and we live together and everything, so I want to take the next step in our relationship (which is engagement, marriage etc.) but he doesn’t want to take that step with me yet because he’s not ready yet. Our relationship is good but I don’t know how I feel about him not wanting to take the next step with me. What should I do 😞