Lots of people struggle to write their own spells, it is something that becomes easier the more you attempt it and eventually will come naturally to you, why not try writing spells with no intent to cast them, use it as a form of practice before you write one you intend to cast.
How long have you been practicing? It can take time to learn and develop the methods of spell casting, it may not be the spell that is stopping you, it may be your knowledge, on the other hand it may be the lack of reality in a spell, or your feelings that because you are dyslexic your spells will always fail, much like a self-fulfilling prophecy.
Being dyslexic shouldn't have an effect on your spells unless you allow it to, I myself am dyslexic and have never had a problem with it in spells.
Emotions are not a flip of a switch, they are a gradual change, i'm not entirely sure what you mean by "two sides", because you are one person, your emotions are controlled by your brain and hormones not the change from one side of yourself to another. I am not sure what "powers" or abilities you are hoping to get from this, but it sounds very bizarre, as we are already one person, you don't have to fuse together two sides in order to make yourself more powerful.
Also if it snowed in September then is has nothing to do with you casting a spell, it would have happened regardless of what you did. Snow is part of a weather system much bigger than just you.