Peace be upon you my friend.
When you said that you heard God speak to you, my eyes lit up. Not to say that we have the same starting point, but boy it surely is similar.
It says in the Quran 4251
And it is for a mortal that God should speak to him only by instruction or from behind a barrier or send a messenger to give instruction by his leave in what he wills. He is exalted, wise.
You talked about seeing a snake or the tail of a snake, and also that you where not to open your eyes until told otherwise..
My real introduction to islam was a result of of both hearing a voice, a voice of awesome might, telling me that I "had to understand" and that I had to fast for 40 days. I also saw an awesome snake slithering on the wall. It frightened me. The whole ordeal ended up with me jumping from a 20 meter tall building and shattering my body. Read my introduction post on this sub-forum for a clearer picture.
So it got me pondering about the whole idea of God and I just stopped after I came home from the hospital, but gradually I found bits and pieces about relying on the Quran and here I am seeking to share ideas and experiences.
I don't understand this verse properly, but given what the verse says you could see that maybe the Quran is the instruction and if you talk to someone from behind a barrier you wouldn't be able to hear, but the words where spoken none the less
So does God talk to us directly like he did with Moses, or are we supposed to rely upon the Quran in order to "hear" God talk to us. I mean in my case, why would the message be so cryptic and lead me to jumping of a buidling believing that I would be catched by angels? The psychiatrist went with psychosis in my case, but I believe that the experience has a higher meaning than medical terms. Given that you experienced something similar it further semets that idea in my opinion.
God bless you.