ahh well...
never give up...keep practising.
I am no expert by any stretch of the imagination but, here's a story about a guy who couldn't sing. And the first time I heard him I thought I was going to die.
This guy ran a little pub ( I think he still does ), and for entertainment, he had a little kereokee show that he let his patrons run. (way cool, but scary)
Anyhow, he used to get up there and sing sometimes, I swear to god every note was out of tune. It was probably the most horrible thing I had ever heard. After a certain period of time had passed I moved out of the area and didn't frequent that bar anymore. One day, I went back there, (about a year or so later) and that same guy scared the shit out of me by singing the same old songs he used to, except every note was actually in tune with something. I'm not saying he was great by any stretch, but definately a huge improvement. I had really thought originally there was no hope, but here I was wrong.
like he said, the main thing is having fun. As long as you are then no worries, just keep practising...lots...and lots. I am sure you yourself will notice an improvement over time.
From my point of view I can't sing a part to the rest of the music for the life of me. I like to think I can sing in tune, but my vocals always clash or just plain don't fit. In that regard, my parts don't go together, yours do.
practise practise practise.