I heard it all; "you guys were too young." You were, "way too naïve." And of course, "there's plenty more fish in the sea." Yuuuuuuuup, this is all very logical. I'm 22, I still have A LOT of learning left to do. Yes, of course, there WILL be someone other than you, & I'm fine with this now. Even so, what I do know is that: my age, nor my lack of knowledge about "love and life," or the fact that I know there will be someone else have nothing to do with how we actually felt about each other and that what we had was damn real.
First and foremost, you absolutely suck, anxiety.