Splenda is sucralose
Which chemically is Sugar where they have replaced a H atom with chloride which makes it 200 times sweeter than the sugar it came from.
Problem is it tricks the brain and makes you crave sugar even more. Most non natural sweeteners do.
Don't use Yellow (sucralose) sweeteners. One side effect is 'may cause diabetes'!
I use Stevia tablets from Tesco and Truvia when it is on offer (far too expensive). Use too much Truvia and it does have a metal side taste.
Use little and it is fine.
What I have found with stevia is that I don't crave sugar as much now. It seems to satisfy the need for sweetness unlike other sweeteners.
Still love sweets, chocolate, but sometimes I forget to sweeten and don't mind.
If you like sweet coffee, try "Camp" coffee with one Stevia. It is made from Chicory and has Inulin in it which is naturally sweet and very good for your gut flora.
You can buy Inulin at health shops online and use it as a sweetener. Only problem is it is also an insoluble fibre and if you increase amount you eat/drink too fast you will get gas problems and become constipated.
The food industry is starting to use Inulin instead of the dreaded 'Fructose Molasses Corn Syrup' that replaced plain sugar decades ago.