Congrats! Fully finishing a draft is a worthy achievement. You should be proud. I haven't yet managed it myself, though I get closer by the day, so I guess you should take what I'm about to say with a grain of salt. I really lost the plot about 2/3'rd's through my manuscript. Characters weren't behaving the way I meant them to, and things somehow started to make... less sense? In my experience, trying to change major things like scene placement from inside your draft is an easy pathway to revision hell. You might find it valuable to set aside your manuscript and focus on reoutlining it from scratch. If you're not sure what that looks like, Outlining Your Novel by K.M. Weiland fundamentally changed my understanding of outlining as a skill. I can't recommend it enough. The idea isn't to immediately make changes, though you certainly can. Instead, it's that the process helps you better understand the purpose for each scene, character arc, and story beat. Then narrowing down on specifically what isn't quite working becomes far easier.
