I am not also experienced in Bitcoin but I have something in mind about what you may do with your portfolio. It's up to you what you want to do when I share what I am going to share.

Choose altcoins that you think that are most likely not getting its price more than 20% or an altcoin that doesn't have much potential and convert it to Bitcoin while the rest you think have good potential stay as it is until next season. In that way, I think you will prevent more loss with its value but for you to stop more loss then buying stable coin is much more recommended since it is much more stable than other altcoin since it is pegged in USD. YOUR CHOICE.