Feeling tired/sluggish + headaches during eating periods as a beginner to IF?

Trying to get into a more consistent 14/10 schedule and after 2-3 days I feel tired and get these mild headaches even during times when I'm eating.

My overall calorie deficit is about 300-500/day from maintenance and I eat pretty clean, so I know I'm not malnourished.

Does this ever pass eventually or I just have to accept this as part of the process?