How do I know if I should choose him?

I’m 28 and he’s 51. We’ve known each other for about five years, and for most of that time he has waited for me to decide whether I actually want a relationship with him.
I feel extremely guilty about that. He has given me so much time, but I’ve never been able to give him a clear yes or no.
The confusing part is that I genuinely love him. When I see his face, I feel warmth and happiness. I love his smile, his eyes, his little sassy personality, and all the small things that make him who he is. I think about him every single day. We’ve talked almost every day for years.
But whenever I get close to actually committing to him, I become extremely anxious and pull back. I’ve been stuck in this same cycle for five years.
He lives in Mexico now and I’m in Las Vegas. He wants me to move there, live with him, and build a life together.
That would mean changing almost everything about my life. I’m extremely introverted and very used to being alone and having my own space. I live with my mom, work, attend school online, and spend most of my time at home with my family and my dog. I’ve never even traveled outside of the United States.
Recently, he started trying to date because he feels like he has waited for me long enough. He went on a date with another woman, and hearing about him spending time with someone else hurt me much more than I expected.
We recently talked on the phone for about four hours. He told me he still loves me and has never loved anyone the way he loves me. He also told me that he doesn’t want to spend the rest of his life alone waiting for me to make a decision.
He wants me to come to Mexico and finally give us a chance.
I finally told him that I love him too.
After we hung up, I couldn’t sleep.
Part of me wanted to say, “Just go. Stop being scared and finally be with him.”
But then I became extremely anxious again and wanted to pull away from everything.
My faith is also a huge part of this. I love the Lord, and my relationship with God is extremely important to me. He doesn’t believe in God. I’ve prayed about him for years. I’ve prayed for God to show Himself to him and for him to eventually want to follow God, but that hasn’t happened.
I know I can’t build a future with someone based on hoping that one day his beliefs will change.
I’m also trying not to let guilt make this decision for me. I feel horrible that he waited for me for five years. But I know saying yes just because I feel guilty wouldn’t be fair to either of us.
At the same time, I don’t want fear to make the decision for me either.
That’s where I’m stuck.
I know that I love him. That’s actually the one thing I’m sure about. I just don’t know if loving someone necessarily means you should build a life with them.
I’m trying to separate what I actually want from my anxiety, guilt, jealousy, fear of losing him, and fear of completely changing my life.
What practical advice would you give me before making this decision? Should I visit him in Mexico first instead of even thinking about moving there? What conversations should we have about faith, marriage, finances, children, and everyday life before I decide? And after being unable to say yes for five years, how would you approach figuring out whether this relationship is actually right for you?