Can pre-load 3 videos at a time and show the middle one to the user. When user click previous button, the current video should be swapped with the already playing the previous one. Similarly, when the user clicks the forward button, the current video should be swapped with the already playing next video.
After swapping the videos, 3 pre-loading video will be updated for the next operation, like a circular buffer, this process needs to be repeated to show all 90 videos.
Let me know if you can do it and when you can deliver the script.