This is kind of difficult to explain (im sorry if its really long) and I haven't found a question yet that addresses my exact issue. Apologies in advance if this breaks a rule, I can't find them anywhere and can't be sure if I remember them all.
Anyway, I'm writing a story where the protagonist spends a great deal of time alone. He thinks to himself things that I'd rather keep secret unless plot relevant, is much smarter than me, and frequently reminisces of scenes I haven't written yet. And I also use the thoughts of other characters to build the contrasting nature of his outward personality and his inward personality. So I figured tpo is the best option (tell me if im wrong). I've never written in tpo before. And honestly it feels like I'm writing more in tpl. I don't know how to write a characters thoughts without overusing pronouns or just generally annoying/confusing the reader. Can I italicize sentences in first person to indicate thoughts? I've always thought that was sloppy. Describing what they're thinking creates a lot of pronoun overuse. Just saying the questions they have is kind of confusing. How much of other characters' thoughts can I incorporate before it becomes a jumbled mess? Right now I have the story starting off with a narrated back story type intro and then moving on into direct dialogue and what the characters do and think and feel and see. It honestly just feels like a mess. I know what's going on because I wrote it but I can't tell if anyone else will. I always tend to ramble and not make sense when I write, sorry if I did that here too