I did mine myself. However, you have not given any reason to believe the timing belt is at fault. In fact, it should not be the belt, as you are still well under the service interval. Consider finding out the real cause of the problem before going into the timing belt. There are three belts on the front of the motor, each with their own tensioning system and rollers. Any of those components could be at fault. Ideally it's something on the outside of the front cover, so you are looking at, say $100 vs. $700 for a repair.
Find out first.