The poison itself should tell you how it is healed (but it sounds like one made up by the GM, so you need to see how they want it dealt with). In the case of attribute damage I thought it was usually 1 point per day of rest, one after the other (so 10 points of Con damage and 10 points of Str damage equal 20 days of rest to remove totally). The not getting help as soon as possible I am assuming made things worse, because that allowed the poison to spread throughout their body, something that is always worse. (Though, funny enough, if the wound bled a lot - I am assuming it didn't as your character would likely be dead after 12 hrs of bleeding - it could have actually taken some of the poison with it, thusly lessening the effect.)
To speed up the healing, you either need to get the appropriate herbs or magical healing. Poison lore could be used to identify the poison and hopefully what is needed to deal with it and its effects. Of course, because they waited, they will most likely just be dealing with the effects as the poison has "run its course."