hmmmm help

When someone freaks out and pulls away because they're scared/ nervous about where things are going and so as a result they're creating negatives that don't really exist, what are some ways of helping or dealing with that? It's killing me and idk what to do. We've been talking for literally about 5 months and properly dating for almost a month now and he's just totally pulled away from me and he knows he's doing it too 😔