Not to burst your bubble, but it is possible that you weren't ever influencing Nature in the first place -- merely exhibiting good timing. Nature doesn't just make it rain or shine for anyone. She has her own agenda, so when casting weather spells it really helps to be in the right place at the right time.
Though, maybe someone else is casting a more powerful sunny weather spell? There are plenty of explanations, but your magick "ceasing to exist" is not one of them. You will always have your ability to work magick. Are there any other magick practitioners in your area? Maybe you could team up and invoke a rain god(dess) or work a rain spell together?
I love rain ^-^ If you look at the Wikipedia page here, on the Japanese weather charm "Teru-teru Bouzu", you can try making one. In the song, where it asks for sun, just ask for rain***:
*** When constructing them, fill their heads with shells, turquoise, and other items to represent rain/water... maybe even make them umbrellas :D I'm going to make some when the weather gets a bit warmer to ask for thunderstorms.