The shivers don't stem from the temperature of the water used, but from the release of old toxins and waste, and stones.
Is there is anything in your bed (synthetic cover, dust mites, etc.) you are allergic to? Does the skin itch when you lie down in other places? Allergic reactions cause such sudden reactions, and also disturb sleep.
If you cannot tell your husband what you are doing, you are basically telling yourself you are not worthy. You diminish your deservability, whereas in truth you have the right to be exactly who you want to be, with and without faults. If anyone doesn't accept you for who you are, it should be their problem. If you believe your life depends on their approaval of you, it is your problem. Not standing up for yourself, your choices, your opinions, but remaining afraid of criticism, is a major source of depression. By doing exactly what you are afraid of, you take your life back into your hands. If others go along with it, fine. If they don't, they need to learn that they can only keep things or people in their lives they love.