wanted to report a problem and see if anyone has any advice for me-

worked out with weights Friday, upper body (do this 3 x wk Mon, Wed, Fri)
For the first time since I started weight training 6 months ago I had kind of
an energy collapse. I completed my first set of overhead press and could not
finish my next two sets. It felt like I was lifting twice as much weight as I
actually was. I did complete the whole workout but it was limited in reps and
sets. The next day I was sore. Should not have been.

That day I did eat a little less than usual before the workout (worked out at
4:00 pm)
and did not eat as much protein. I ate half an apple at lunch (with other
food-meat)which is a new item added to my diet as of late. I eat mainly meat
and do take supplements. After the workout I felt weak and slightly nauseous.

I eat, generally, a low carb diet, less than 40 grams carb per day.
I lift weights fairly intensely on the 3 upper body days. On Tues and Thurs I
do lower body workout. All five days I train my abdomen. I work out on
weekends sometimes but not always.

I figured I ran out of glycogen and my muscles just couldn't perform.
What do you think?