Hi Subatomic star
Couple of questions for you:
1. What's your natural singing range?
2. What part are you singing in choir?
3. Are you singing that part because it's comfortable, or because there is a shortage of people in that part?
I used to sing alto or even tenor in choirs if that's where the gap was, even though I'm really a fairly high soprano. As a result, because I was filling a gap and was outnumbered, I tended to oversing (or, if I'm really honest, to shout). And so my throat hurt horribly after rehearsals. In other choirs where I sang soprano, I tended to sing loudly to try to drown out other people going wrong (yes, I know, I was horribly arrogant!

)
Many years later I learned that trying to sing loudly using muscle power is a bad idea - singing shouldn't take much more effort than speaking - and that relaxing and using my abdominal and tummy muscles as nature intended to drive my voice (rather than using my throat) actually results in much better projection (and a nicer sound). As my singing teacher put it, I stopped trying to sing from the neck up and started using the whole me.
So I guess the point of this ramble is, make sure you are singing in your comfortable range, and don't force your voice louder to compensate for others.
Hope this helps
Cheers
Katyjay