I can help you out by saying that there's no C major chord in crushx3 (the barre chord you're playing from the eighth fret). You've worked it out by ear pretty well, but switch C major to C minor and you have it sounding like it's supposed to! (the song's key is, after all, C minor (or C# minor in the studio version)) You're right about "the part between the first chorus and second verse", the very last chord that you seem to have trouble working out (that you skipped over totally), is actually a C5 chord with B on the bass, or B5+, played
10
7
or, if you want to extend it,
19
10
7 (first inversion of the dominant for the theory geeks, amazing trick that's made its way to hundreds of radio hits.)
Trivia: My theory teacher called a G#, A#, C progression, with all major chords, a "Eurovision ending". I guess it's because the last chord is supposed to be a minor chord, but switching it to a major chord sounds super happy.