Need some advice on my relationship?

Hello all. I have been with my girlfriend for about 6 months now, and we're both 16 and in the same high school. My girlfriend loves me a lot for sure, and i'll never doubt her faithfulness. She would NEVER leave me for another guy, thats for sure. The thing is, recently, i've been worrying a lot over the issue of losing interest. I'm often worry whether i am losing interest of her or not, and i'm always fearful that we break up because i have lost interest for her. Every now and then some things such as me getting annoyed with her easily or such as today, i suddenly didnt have the mood to argue with her and it would remind me of losing interest. Is it me who's too worrying or the fact i really am?

Just to add on, nowadays our texting has been getting really dull but in real life we're both still pretty much the same, no awkward silences, always talking etc.

Well the honeymoon is over and now everyone is showing real colors. If you break up thats only natural. Things are going as they have to go. Refreshing thing for relationship could be break up. Not like breakup when you both still stay in same town but breakup for example when one have to leave for trip for few weeks or visiting distant relatives. These kind of things makes relationship stronger and time apart give a chance to appreciate more your partner when he was near.