Been working lots of OT and at night I’ll feel a tad bit spacey. Am I just tired or suddenly have blood sugar issues

I’ve been working 12 hour days which includes 1 hour lunch. I work from home doing call center work. I’ve been getting up at 7:15 and working at 8am until 8pm. Usually morning is kinda busier than my normal afternoon shift but around 4pm things really start to slow down. To where sometimes I might not get a call for an hour and then I might get one and have 20 mins between a call. Some calls are stressful but I normally work 9 hours a day without OT. I do stand randomly during my shift and while walk in place when I have lots of down time so I am moving about 30 mins a day and averaging about 7-8k steps. Been making sure I eat when hungry but around 6pm-9pm it depends I don’t get dizzy but I get a tingle in stomach when I move my head around or I feel light on my feet but spacey. After my shift I have to sit in silence for a bit to relax. I had dinner right after my shift and about an hour later I got that feeling, had some Cheerios last night which helped the feeling a bit but I still felt that way just not as bad. When laying down I could feel my heartbeat in my head. Been trying to get 8 hours but have been on average getting 7 1/2 or 7 hours and 15 mins of sleep. 3 years ago I had pre diabetes which I reversed but kinda worried what I’m having is low blood sugar or is it just stress? Also been making sure I drink water too