Well that is not hard to fix. First are you using pivot for these? Also how many frames is this? I can help you make it slower if you tell me these things. Then you can just re-upload it at normal speed.
Tip: Don't make words only one frame, make them multiple frames, and in the end; give like 4 or 5 extra frames just so the viewer knows it's the end. (if you are using pivot)