Not eating enough & 2 much exercise be causing nusea all day

Sevio

Anyone experienced this?
I have been feeling nauseated for most of the day (mostly at work) and am wondering if my calorie intake and amount of exercise is not meshing.
I eat around 1600 to 1700 calories per day and per roughly burn 700 each day per my Fitbit. I go to Curves Monday through Friday, walk on breaks and lunch and walk my dog in the evening. I have been at this weight loss for over a year now.
It's been going on for a couple of weeks now and I can't be pregnant. My weight loss has pretty much stalled in the last few months.