I've noticed the same thing. I would have three, sometimes four sessions run at the same time. It would be great, but mentally exhausting. To help this, I've set a self-imposed limit of two active chat sessions at a time.

Another thing I found is that it is too easy to keep going. I would work for too long and get even more exhausted. It feels rude to just stop a conversation. LLMs don't really care about social norms like that, but it still felt awkward to me and I would worry about losing the context I had.

To help with that, I wrote my own little plugin that reminds me to start winding down at the end of the work day and starts prompting me (pardon my phrasing) to take the off-ramp; to relay any thoughts and todos I still have in mind and put them down to pick up the next day.

This is in no way production ready, but it might be an inspiration: https://github.com/pindab0ter/wind-down