Hello Ageless! I'm having a comment regarding your discussion about the shaking/trembling, and whether fear may be the reason you're experiencing it or not:

Although I'm a beginner, I've also experienced this phenomenon. One time, I managed to get a very pleasant orgasmic feeling linked with much of the same as you're describing in this chat; some serious shaking of the hands, a very high heart-rate and tension because of the excitement I got at this point.

So even if I'm not an expert on the field, I think that Jack may be right about that the orgasmic energy is the reason you're experiencing these kinds of shakings!

Wishing you good luck! :)