What emulsifier will help my (nearly carb free) Milk Chocolate? I'm a Type 2 diabetic and maintain ~ 20g carbs per day. This is great on my numbers, but hard on my sweet tooth :)

One of my favorite treats to make is a simple mix of Virgin Coconut oil, unsweetened coco powder, and Splenda. This combines into a surprisingly smooth thick chocolate sauce that in the fridge hardens into the consistency of a chocolate bar. Yummy!

Recently, I tried to up this to "milk chocolate", simply by adding a bit of whipping cream to the mix. This actually tasted quite amazing, BUT the oil and milk separated like crazy.

I believe I need an Emulsifier to resolve this. Can anyone suggest an Emulsifiers that I can buy in a store and use for this blend? Ideally it should be carb free and mostly flavorless. It can't be egg yolks because this isn't cooked. I read that in real Chocolate making, Lecithin is used, but I also read that Lecithin isn't actually an emulsifier...

Anyways, if anyone knows the chemistry of what I should do here, I'd really appreciate it. Also if you can guess at an amount of Emulsifier (to Roughly 3 to 4 tablespoons of chocolate "goo") to start with, that would be awesome as well.
Yes, an emulsifier is the way to go. Lecithine is an emulsifier, and will work. The downside is that it might impart a slight eggy taste, I don't know if this will be a problem for you. Also, it is a bit harder to store than the other emulsifiers, it tends to lump from ambient humidity. 

The more common emulsifiers for your case would be xanthan or guar gum. They are not carried that often by stores, although I've seen guar in a health store. But they are quite easy to purchase online. Any of them will work well. The biggest challenge is to disperse them evenly in the food. I would recommend taking a teaspoon out of the cocoa powder, mixing the emulsifier with it (dry), then mixing that teaspoon back into the complete amount of cocoa, then proceed as usual. 

You don't have to fear the carbohydrates from emulsifiers. All three will work when used in tiny amounts, about 0.5% - so you can get away with 0.5 g emulsifier per 100 gr "chocolate bar", which shouldn't be much even if they are pure carbohydrates. (Xanthan and guar are carbs, but they are polysaccharides, and I have no idea whether they are insulin-active). 

This will help you make your chocolate bars. On the other hand, I don't know if making them is helping you at all. Cocoa powder is 60% carbs, and splenda is 90% carbs. A true chocolate bar (the good brands) consists of cocoa solids (which is cocoa powder + cocoa butter before being separated), and sugar. If you are using the same proportions as in a typical chocolate bar, you are getting about the same amount of carbs from your mixture. It may be a tastier way to temper pure chocolate (unsweetened chocolate) together with some fat until you have reached a carb-to-fat ratio sufficiently good for you. Adding cream is also a possibility, as well as other flavors (vanilla, orange essence, whatever you want - basically unsweetened truffle making). You can also add pure artificial sweeteners to your mixture, which are not bulked up with carbs the way splenda is. This way will be more expensive and time consuming, but will give you a better quality end product.