hey there! it's been a while since you posted this question. how's your voice doing?
i'm really new to singing -- have in fact only started singing a little over two months ago, when i started taking vocal lessons. i'll try to give the best advice i can from what i've learnt from both research and lessons so far.
from what you, and some others have mentioned, it seems like you have been trying to hit high notes with your chest voice, which frankly, can be awfully straining and damaging. if possible, get yourself a vocal teacher, and if not, get Brett Manning's Sing Success, as suggested in an earlier post. the technique taught in that course is SLS-based, which will teach you to sing with a mixed voice (i.e. mix of chest and head voice). you could also try researching "mix voice", or even "vocal cord closure". maintain closed vocal cords while singing will help give you a stronger, more resonant voice, and even extend your range i think.
be sure if vocalise everyday, and don't give up hope:)
true story: before i started lessons, I had trouble just hitting middle C, and was convinced i was of the bass-type, which i later realised i wasn't. my teacher diagnosed me as a baritone, though i do have a low speaking voice. after a little over two months of lessons and (near) daily practice, i can hit a high E (E5). i won't say the middle octave is a total walk in the park for me, but i don't have to strain my voice to hit notes within it.
you might also like to know that though some male singers sing high notes with a strong voice that resembles a chest voice, it's very possible that they're using a "mixed" voice.
as was suggested in an earlier opst as well, try making siren sounds and go up and down your range. go as high as possible without strain, don't be afraid to go into your head voice (that voice that makes you sound like an opera singer). that is what you should be using to hit high notes -- your head voice, not your chest voice (i.e. the voice you talk with).
as you sing higher notes, the moment you start feeling some sort of strain, that's a sign that you should be adding in, if you aren't already, bits of that operatic voice. don't worry if it sounds well, operatic at first, you'll learn to balance your voice out, so it won't sound that much like that, nor will it sound like you're straining to maintain a strong "full" voice by squeezing your vocal cords to keep in chest voice.
side note: if you find yourself singing the higher notes with a breathy voice that you have very little control over, that's falsetto, not head voice. you'll usually get that after having pushed your chest voice right to its upper end, and then push some more. you'll break into that airy voice as mentioned. you should start transitioning into head voice waaay before that happens, around when you first feel strain, as mentioned earlier.
hope what i've said made sense. i'm definitely not the best person to be explaining all of this, especially when i can't demonstrate it. like i said, get a vocal teacher, or Singing Success...or both:D
hope i helped at least a little. take care of your voice!:)