The thing I do is I just try not to worry about it too much, I feel like if I do I'll end up in that sort of situation.
In this post, however, this is just my opinion. I'm definitely not saying to abandon relationships as a teenager altogether, I'm saying that I feel like it can kind of ruin the meaning of love and have a negative affect on your life as well if you become too entangled in it.
I have had two relationships before, and I like to say I was really satisfied with them, even if they didn't last.
I'd rather not see people get into relationships just because "everyone else is in one" or some sort of pressured reason like that. I think it should be something you find on your own, at your own pace.