Going from one tense to another is messing with my head

It's so weird. Before my first book, I only wrote in traditional past tense story telling. But for my first story I wanted the book to feel like you were reading his inner thoughts as they were occurring, so I wrote the entire thing in first person present tense and oh boy, I did not expect it to be so difficult going back to past tense. I'm sitting here having to rewrite every sentence because the way it comes out initially is in present tense, but that's not what I want. I know it'll click back eventually but it's just crazy to be right now, lol.