All of a sudden having issues...

So the last two mornings I have become lucid, however; not from reality checks just noticing differences between reality and dreaming. Actually this morning, I tried to push my hands through and it was a false negative and then I did the breathe through my nose while covering it and that worked. I have never done these as checks, I used to always use time or writings. I'm not sure why it's changing. But anyways the problem. Most times I am lucid I fly, all of a sudden the past two times, it didn't work. This morning, I was in a house and I tried to fly through (which I have done before, the house/roof just splinters around me), and it couldn't, I would stop parallel to the ceiling and it felt like jumping through honey. Then I went to try extra hard and closed my eyes for too long and I woke up. Yesterday morning, same situation, couldn't fly, thought to try teleport, but as I started floating, I closed my eyes for too long and woke up.

How can I make sure to keep my damn eyes open?!
Why am I all of a sudden having problems with flying? I never have and I was a natural, never had an issues even from my first lucid dream.

I'm not an expert lucid dreamer, far from it!

but..everything is in your mind, you need to truly believe that you can fly and you will. The second time it was more likely not too work, as you weren't as confident of it working from the last time.