The nice thing about the teen program is that you can choose to participate in the activities or just hang in "The Stack." THere is music, reading material, computers, etc, as well as just hanging with people your age.
My daughter has found that the key to a good cruise is making a friend in the first day or 2. You might try the cruise meet section or come to chat on a Fri. nite and see if there is another teen that you can communicate with on line before your cruise.
DCL has movies, stage shows, variety shows, games/contests, hanging in the sun...all in addition to the teen program. The teen shore excursions are wonderful. Seriously, if you can't have fun on THIS cruise, you really aren't trying. There really is stuff for everyone of any age.
My "cruising partners" have ranged from age 4 to 49, and ALL had a blast. There are a lot more young people on board if you are travelling on a school break...but there are always some at any time. There is one dining room rotation for adults travelling alone and families with older kids (like 10 and up), so you won't be overwhelmed with little kids at meals either. Will "The Stack" keep you busy all the time? Probably not. However, we've found that the real issue is that there is more to do than we can possibly fit in a day, not that there is a lack of stuff
There's a teen party EVERY night.....different theme each night.
Have fun.