I have a problem, but cant pinpoint it

Ok so I will quickly establish that I love my boyfriend dearly, he's wonderful and all that I could ever hope for, but recently I have started to worry, a lot. It is extremely confusing because I can't settle on something i am solidly thinking about, one day I am worried that we won't really last, the next I feel trapped, then I am not even worrying about him exactly I'm just depressed in general, and still other times, I feel really lovey and hopeful, on most days a vatriety of these happen at different times of the day.

I have been experiencing other symptoms of PMS and possibly even a hormonal imbalance or something relating to that ( I am 16 ) the doctor did say I have anxiety, is that some of it??

This is extremely discouraging because I was blissfully dating him for almost half a year when this hit and it has been continuing for a little over a month, its disturbing, does anybody have a reasonable explanation for me? I'm kind of lost I have been known for wording, is this something I've just been taking to far? If so, how do I stop?