Practicing means hard work and lots of rests inbetween. When learning how to play an instrument I have to throw myself in it until it scrambles my little brain. Then when I take a well deserved break (couple days or maybe even a week) I go back to it and I have learned and improved.
SO I do understand about throwing yourself into a creative spot. But when it starts getting tedious, well...just rest and don't stress.
A good work ethic is always needed for success.
Lyric writing (write every day and finish each song) even if you think it sounds rubbish.
production: produce and finish it!
Sing and use your ranges and use the elements in a song!
How often should you do this? I think atleast an hour on each one!
Long and short!
Produce a track in less than an hour.
Produce a track in less than two weeks. (makes sure you complete it)
How often...as often as you can.
treat it like your 9 - 5.