SL's book is amazing . If you still have it, I would recommend reading it over again after all these years. You'll probably catch something you didn't notice before.

Waking up too early is a good problem to have. It's a milestone to get to the point where you will sometimes recognize you are dreaming. Start doing the practices again to get yourself back to that level. Once you recognize that you are dreaming, without hesitating, immediately begin to spin like a top. Keep spinning until you feel the environment stabilize and when you stop feeling like you're going to wake up. This has worked for me and a lot of others. The idea is to overstimulate your dream senses with dream stimulus to make the dream environment feel more real and present.

As far as the sleep paralysis, that can definitely be a frightening experience. I've had it several times myself. The key is to recognize that you aren't in any real danger, and to see it as an opportunity to more easily Astral Project. If you find yourself in that state again, just stay calm and start practicing the technique that I describe in this post. You will probably be able to astral project if you start from a position of sleep paralysis. Good luck! Let me know how it goes!