Sick from artifical sweetners

Hi ,
I have been back to no carbin for a week in a half now. This is old hat to me been here before. something new has happened to me this time I quit sugar. I have always replaced it with Splenda or equal. This go around I have gotten so sick from it . I feel nausiated,headache,night sweats(too young for the change of life ha ha). I am wondering if there is anyone else out there who is going through this. If so what are you useing for a sweetner? kinda bummed