Not to be harsh, but you’re overreacting a massive bit. I genuinely think you’re not mature enough yet for a relationship, and not because of looking through his phone but because of the absolute histrionics and self-victimization of this post.

An example: at the start you state that you’re disgusted that his search said teen and then say that you were 18 when you started dating and that he was “older”. You omit his age to try to manipulate people into thinking he’s a creep and the implication is that he may have chosen to date you for your youth only to reveal at the very last moment that he’s a mere 4 years older than you, as if a 22 year old dating an 18 year old is problematic the way a 30+ year old doing the same is.

Your whole post just oozes immaturity, and please understand, that’s ok! You’re 20 and a lot of people your age are. You have the opportunity here to really reflect on yourself, not just around your choices, but your responses in life as well. Please break up with him and take the time to learn how to strip the dramatics out of how you engage with the world and I promise you’ll find yourself in a much better place to enter a relationship healthily. Your current BF doesn’t deserve to be with someone who disrespects his boundaries or who is essentially staying with him for his car.