Nope not just you. They are very similar (especially if you learn the guitar parts, a lot are set up the same). But it hasn't bothered me really. The only time it was bad for me was almost every song on the Sekrets album I could find pieces that would fit perfectly/sound exactly like songs from this addiction. Like same melodies and everything. Still catchy as fuck so it's not a huge deal to me.
it's silly to pick apart their songs, and people do it so much. At heart they're a pop-punk band based around three chords although they throw an occassional riff in here and there. I'm not certain of the exact number but they're pushing 120 songs written in their career. At least they've done a better job of not repeating themselves as much as a band like NOFX or Green Day. Like you said, catchy as fuck so I don't care. I feel like everybody needs to be this critic and analyze shit til they suck the joy out of everything. The internet wears me out sometimes lol.