Each voice type is somewhat different in how they are able to achieve higher notes just as each person's voice is different. Breathing is essential for any type of singing be it high, low, sustained, whatever it may be. That's the first lessons that anyone will get when they start training. It's just good for a refresher. Though it may sound like some of this advice is more "classical" singing rather than popular, the techniques are the same. I would suggest building the natural voice, i.e., don't strain or push for a note, and find someone who teaches belting lessons. Belting is it's own technique and require specific training just like screaming does for "screamo". Best of luck to you!
P.S. most "belters" are actually low sopranos and altos. Keep at it smile