Hi - you started by saying when you focus on study you cant focus on others but later the problem statement reveals that when you are doing something you are actually going into a dream world. so coming back to first line - are you really studying or you just sit with the book but go into your fantasy world?
Next Steps
next time when you are doing something . .start to think/feel what you are seeing? what you are hearing? what you have to say? what you feel at that time? give work to all senses ..
Health Tips
Do you sleep enough? Have healthy foods? These two are important for our bodily functions to be normal. If they are normal try doing what i had mentioned above and provide updates