Good morning. I love my coffee sweet.

In an effort to save calories I use 2-3 packets of Splenda in each cup averaging 2-3 cups per day. I have looked online & found some articles stating that Splenda is formed from combining chlorine & ammonia at high temps

which doesn't sound to healthy to me.
I think we're brow-beaten by the mass-media to see the word "chlorine" and freak, but that would just be a reflection of a misunderstanding of chemistry, though. For example, while hiking in the backwoods, your best friend is chlorine or iodine. These chemicals, used with acumen, make water
safer.
In the case of Splenda, there is no evidence that the chlorine used in its processing has any
more negative impact on your body
than regular sugar has on your body, including its contribution to unstable blood glucose, obesity, diabetes, heart disease, immune system problems, etc. There are many people who beat their chests and wax poetically about how they only use regular sugar, trying to make a heart-tugging self-promotional appeal advocating regular sugar as a better option... There is no evidence of that.
The negative ramifications of eating too much sugar are painfully clear, ridiculously obvious, and inescapable. Meanwhile, while nothing is ever guaranteed, Splenda seems, on every level, a positive alternative to sugar. So unless you're going to abandon sweetness altogether, don't give much credence to those who try to scare you away from Splenda. Make them prove their point on a same-versus-same comparison, sugar versus Splenda, over the long-term, with a whole-health perspective, not convenient self-selection of unrelated science experiments that have nothing to do with how the two substances will affect your body
and your life over the long haul.
All critics are
legitimately able to advice you with integrity is that you should learn to live without sweetness, entirely. There's clear evidence that that does have overall positive impact. I'm not willing to make that choice.
I figure over the course of a day I probably have the equivalent of 10-15 t. of sugar - so just a little more than you. I should note that I do not drink diet sodas (anymore), because the acid messes with my digestion, so coffee (which has acid as well, but it's a good trade-off) is the entirety of my sweetness consumption, with the exception of a bit of "medicinal"

dark chocolate each day. So either I use a little more artificial sweetener than you, or a little less, if you're a diet soda drinker - and I'm very comfortable and confident in my consumption choices in this regard.