You're not Alone. It affects me too both personaly and professionaly. What I noticed so far is that if I get very very busy at work, like non-stop things to do at work I manage to daydream less. It also helps to sleep well at night. If I'm not tired I can concentrate better at work and Stay focused for longer. Of course that as soon as I have 5 minutes I drift off to daydreaming again. I Will always daydream and I'm sure you Will too, and I also would like a solution to be able to chose the right moments to daydream and the moments to Stay focused, but this is what I noticed in myself so far. I understand what you're feeling but I thought about it for a while (daydreamed about it really) and you can't lose yourself if it's who you are and it's part of your nature. You were allways like this, as you Said it begun in childhood like most of people like us did, from what I could tell from other posts, so... It's who you are. All you have to figure out is how to manage and try different things to be able to focus so it doesn't become a burden for your life. This is my point of view, maybe I'm wrong but I hope it helps.
Hi Blackieclone, and welcome! One way to reduce the amount of daydreaming is to find the moments and activities that bring them on. So if you find you daydream longer while you're taking a bath, take shorter baths. If you daydream longer and more intensely before bed, try going to bed when you are quite tired, knowing you will go right to sleep faster, rather than go to bed hours earlier to linger and daydream.
Changing your behaviour changes how you daydream. Also, with that said - you may want to be productive in other ways that actually keeps your mind more busy or deterring from daydreaming. So if you find that cooking or gardening or doing something with friends tends to be more productive and you find during these times you daydream *less*, then do *more* of those activities.
I hope this helps! For specific tips you can browse the forum or find other outlets online that talk about how people have managed to reduce or stop their daydreaming. Good luck!