Where wild minds come to rest
My daydreaming is also at an all-time high right now so I feel your pain.
As for what works for me, I find it easiest to stop the daydreaming when I'm surrounded by others. If I'm left alone, I'll do nothing but daydream or do research for my daydreams. I also try to keep the daydreaming limited to a couple hours at night after everyone else in the house has gone to bed, and for an hour or so in the morning before I have to get up (but it doesn't always work), and I keep a journal of my daydreaming. I write about what's happening in my storyline, how long I've daydreamed for that day, and what is going on in my life and my emotions. That helps me a lot and allows me to look back for patterns or triggers.
Keep busy, try to avoid any known triggers, be with others as much as you can... whatever works for you... and continue reaching out to everyone on this board so you remember you are not alone in this struggle. Focus on small goals. Try to keep yourself involved in another task if only for 20 minutes at a time. Just don't beat yourself up if the daydreaming happens because it will. Small steps.