Sounds like you will need to have the wheel rebuilt.
$25 for new spokes and nipples
$30 to $40 for the labor
Granted the shops around you may have differant prices but thay should be some where around that.
Also, you may have distorted the rim to much by riding on it with the loose spokes and need an entire wheel but I would suggest taking it to the shop and asking them. Hopefuly they will not try and sell you a new whell if you do not need it.
Oh yeah, you could try and do it your self. If you want to give it a go check out this site
Wheel Building
It will let you know what you need and walk you through the steps to build a wheel. Best if you print out the instructions.
After building the wheel you could just take it to the shop and have them true it for you which should only run you a few bucks.
Hope you get it fixed soon
Slainte
