Keto Diet Question

I am just wondering about a symptom that I have had since beginning the keto diet. I am experiencing stomach tightness...it’s like I did 1,000,000,000 crunches. I keep seeing Keto Flu symptoms online and one of the ones listed is “stomach discomfort” but that to me, sounds more like indigestion type pains. These are more like I worked out...but I didn’t work out this week. I’m just confused. I’ve been happy on the diet so far though. Not really hungry which is one of the symptoms of ketosis I think.

I think I am experiencing that Keto Flu thing because I’m kind of feeling low on energy and last night I ached all over and I’ve had insomnia for the last two nights...that never happens to me!! Usually out like a light!

Anyway, what is this stomach tightness I’m experiencing? I told my mom and she acted like it was a good thing, yet she didn’t know what it was.