Oh, Julie, hunny..
I am so sorry you are having these mood swings. I agree with everyone that it is probably the big change in eating habits... messes with your serotonin. Talk to your doc if this goes on for much longer. You may have to up the dose a little until your body settles down.
Other than that, about the mood swings, I mean, I am the wrong person to ask; I am bipolar and have mood swings anyway when my meds are not right, which FORTUNATELY, they have been right for about 2 years, give or take.
Big hugs and special prayers!