Chip, your temp swings are normal, and it looks like you're in a "secondary" stall...it happens sometimes. It won't last as long as the first one. Go ahead and crank the temp to 240, and pull it out at 195 IT. Shouldn't take long now. Remember to double-wrap in foil and let rest for a minimum of 30 minutes, but 1-2 hours is best.
I usually use 235 for butts with no problems. 225 takes too long.