Can somebody help me with a tomato relish recipe?!

Here is a nice article on using sugar substitutes. It may help you.
http://homecooking.about.com/library/wee…

Salt substitutes:
http://www.associatedcontent.com/article…

there are recipes available if you look at the Splenda site but to a diabetic doesn't mean that we cannot have sugar at all ,we just need to limit our portions and avoid eating sweet too often ,as for the relish ,i;m sure that your husband doesn't eat the whole jar at once but only uses 1 tbs of it .

http://www.splenda.com/living-with-diabe…

Here are 152 recipes to look through:
http://www.cooks.com/rec/search/0,1-0,gr…

I have read that they can have a certain amount of sugar each day. Does your husband take only a bite or two? If so it will probably be okay to make the recipe with sugar.