Recently I have been having loads of trouble trying to sleep. School holidays have recently concluded and for its entire duration I was trying to astral project (I normally take breaks if I get a series of attempts where I don't reach the vibrations). I adjusted my sleep schedule slowly, getting ready for the school week. When I try to sleep I can't. I just lay in bed for hours. I try every 'remedy' I can (like the breathing method) to help me sleep but it dosent seem to work for me. I fear that I am so used to trying to achieve astral projection that I have momentarily damaged my ability to fall asleep with ease.
It may be your body is still adjusting to your sleep schedule. But I think the most likely cause is it's part of your nightly routine to try to astral project, so now even when you don't try your body is waiting for it it's become a habit. Try to be patient and it will work itself out.
It seem to me like it habitual for you body to feel like it needs to lose that energy as a nightly routine. I would suggest take a couple of days resting meditating anything you do to feel happy and alive. Feel the energy being replenished and gradually your body will be able to tell the difference between when your trying to slip in astral projection and when your sleeping for that I suggest not doing it every night.