Once again thank you all for your input and once again I apologize for the confusion in the Enchanted Item department, I just gave them simple names hoping it would make things...well..simpler.
You might consider house ruling that potions cause nasty side effects if used more than one per scene (Storm Front). In fact, that wouldn't be a bad addition to the RAW as it's definitively canon.
The pocket watch number two (you did mean two separate watches, right? not one being both a focus item and enchanted item?)
To be honest I thought the two potion at once was already somewhere in the rules because it was (like you said) clearly in the novels. Now that I think about it I don't think that I ever saw it in the YS or OW, I just assumed. But yes I agree that should be the case, especially since my guy's potions are two to three times more powerful than Dresden's. And yes they are different watches...I didn't notice that I had two of them, will change that now to avoid confusion.
I'm not saying the GM should nerf their ability to be used but giving you enough headaches using them that the character isn't scene stealing every time wouldn't be a bad part of a solution. It would even be a good way to gather up fate points if you had an aspect like More Stuff Than I Can Keep Track Of. Which might be invoked to find it anyway if you missed a Lore role on having the potion you were looking for. Or something similar. That's just off the top of my head, feel free to modify as you see fit.
I also like the thought of adding an aspect that can be compelled so I don't have the right potion. To be honest I always struggle with aspects, they always seem to either be difficult to get compelled from or difficult for me to invoke with a chip, I have trouble finding the balance, and of course they also should be cool and/or interesting. I included an aspect referencing my plethora of both Enchanted Items and potions "I'm a human Swiss Army Knife", but now that I look at it I see that it cannot really be used by the GM to compel me that I'm missing the current needed potion. I thought about "Just the right stuff", I can use it to declare that yes I do have just the right stuff, or the GM can compel me saying that no, you do not have just the right stuff at this moment.