Behavioral changes like that often are responses to a change in the snake's environment - one that the snake doesn't like. Soaking in the water dish is not unusual in itself, but if (s)he normally doesn't spend time in there but does now, it can indicate either a) the beginning of a shedding cycle, or b) the interior of the enclosure is too warm and/or too dry. The nostral damage suggests to me that it's the latter. Set up a thermal gradient within the enclosure (using a heat pad or other heating device - not a hot rock), and this will allow the snake to more or less pick his/her optimal climate. I also might place water containers in both ends, to see which one (s)he prefers. Monitor the temperature/humidity inside the cage, preferably at both the warmer and cooler ends.
Hope these ideas help. Keep us posted... michaelb