It sounds to me like there are several things going on for you. The divorce is one. That's HUGE. You also want to be married to him & he is your best friend. & you have never lived on your own.
That's a lot unknown on the horizon.
I am flabergasted at how frightening in some ways (& we are only to fear The Wrath of God so I do not living in fear mode), but the unknown is a bit scarey, IF you can TRY (which isn't easy at times but usually is the best to do) think of the changes as challenges, growth, places where you are able to empower yourself & with GOD.
I was married to my best friend (even though he didn't act like one many times), had what I wanted, was happily married (despite the abuse I loved him & wanted it to work). So moving back out of that comfort zone to, "divorced," is a place that is unknown & very uncomfortable for me.
If you can think of the fact, in your new home there will be peace, fruits of The Spirit, are, peace, love & joy. If he is not wanting the marriage then you will at least have the peace knowing that you have given him the desires of his heart (even though he may have No clue what that is/ don't forget that part!). & he is not Really a best friend or a friend at all to want a divorce after he commited for life & then wants back out when you want to stay married to him & work on things. So, you don't Really have a best friend, you are his best friend, he's not your best friend. The divorce itself is hard work, it's major life change, but many people divorce, some desire it, many don't. Life goes on. Maybe not as we would like, but God Allows people to make choices then HE Judges us on these decisions we make.
I think the divorce has been the most traumatic experience I have lived through. BUT, what you have learned, what you do know, that growth in life you have achieved does NOT disappear!!!
We move upward & onward in life, maybe stumbling, there is not perfect but for God. & frankly I do believe this is sometimes the point of it all.
I pray the pain is lessened for you & that God's Will comes about & you are @ peace. I'm still in grieving stages of my divorce, yet many unknowns but there is also much resolved that was not at first & I am starting to see choices again as to moving on.. slowly.. & with God's Love.