Diagnose my struggles

Hey,

I started singing about a year ago. I've improved a lot and strengthened/flexed my voice a lot since I started, but I've hit a bit of a plateau in the past month or two. I've not had any voice instruction aside from books/CDs/youtube/etc. I'm probably a tenor, but I'm not really sure. My most comfortable range is maybe C3-G4. I can hit up to maybe a C5 or D5, but my tone can be shaky above G4 depending on the song.

Right now, I sing daily and run through some boring humming/lip rolls/tongue trill/slide type stuff to warm up a bit. I've been less-than-dedicated to the method I was working from before (Brett Manning's Singing Success) because I stopped seeing really clear results after a while. I'm all for consistency, but I think I need to redirect my efforts a bit.

Can you guys listen to a couple of mp3s of me singing? I have one example of me singing a song that's pretty comfortable for me (Science Fiction Double Feature), an example of me singing a relatively low range for me (Bad Things) an example of a few higher notes (the end of variation-on-a-theme) and a couple songs where you can hear me struggling/straining (Caring is Creepy, Heaven is on the Ground). The recordings are all lo-fi, quick-and-dirty affairs, but hopefully they get the point across!

I'd really love some advice about reducing the strain that you can hear in my voice on songs like Caring is Creepy. Obviously I'm straining at the top of my range, but there must be hope, right?

Let me know what you guys think I ought to work on. Thanks!

http://www.soundclick.com/bands/default.cfm?bandID=922739

Science Fiction - definitely right in the pocket range wise. Love the falsetto part and the perfect slide back to regular voice.

Caring is Creepy - definitely straining in spots to reach those high notes.

I think with exercise and coaching a person can reach high(er) notes. But I also feel there is a limit to how high you can go. Eventually everyone will reach that limit.

Keep practicising. It's inspirational to hear you are doing all that you can to improve/strengthen your voice. Good Luck!

Yeah, that cover of caring is creepy is real mess. I tried to find the best example of me struggling. But, the part that interests me is that I can sing those notes (A4 + B4) in other songs, but that particular song will give me struggles. For example, my A4 with a falsetto tone in Science Fiction or the variation-on-a-theme are both pretty clear. In other songs I'll sing it with a fuller tone and that works fine too.

However, in that song, I always feel like I'm running out of breath and straining. Also, I think the shape of the melody is difficult to sing well because it has many jumps and dips. Can anyone offer any advice for those particular problems I had?