An age old question Alyx, and a good one. I, too. started writing at an early age, so I am pretty familiar with this.
The most important thing to me was that I couldn't stress on not coming up with material. You have to ride your strength and believe in yourself. This means simply that you have written before and you will write again.
I read your piece 'Your eyes, My eyes', and enjoyed it. I am quite certain that many thoughts and feelings went into this piece, probably more than made it on the paper. Possibly you could read through it a few times and relive those feelings that created that piece and find something in there new. You have changed a bit since then, maybe the relationship has ended or changed in some way. This will have built new experiences to draw from and can give you material stemming from that. Just remember, no matter how bad something is, there is always something to be gained if you look hard enough. Sometimes that belief is exactly where my new ideas come from.
You have written before, you will write again. A lot of poetry comes from a place that can't be coaxed or controlled, for certain mine does, and the best way to encourage that area is to remove the pressure and embrace whatever comes out, even if it's anger.
I wish you the best of luck; you won't need it, but I'd rather be lucky than good any day of the week.