Patience is key in this end of the hobby. They're called "aquatic gardens" for a reason. Odds are, after 2 months, your moss is already lightly attached. Wait another 6 weeks or until the rubber band breaks. When I use rubberbands, I don't remove them until they disintegrate enough to remove themselves. Next time, try black cotton thread; it'll dissolve on it's own and is harder to see than rubberbands.