I get the same thing. For me it kind of feels like my forehead is going to split open and my brain is going to Vomit from my head.
Not like a headache, but rather like a weird mental pain. That is caused more from my Severe depression than from my anxiety.
I'm not sure what a brain "flexing towards the frontal lobe" would feel like, but it doesn't sound pleasant. Add in being dizzy which makes it difficult to drive at times, and I think what you need is a visit with your doctor. I can't say that it's anxiety as I'm certainly not qualified to give you a dx on-line, nor is ANYONE, not even a real doctor and I would hope that you NEVER accept one.
Maybe this sensation is normal for YOU, but it's onset appears to have been somewhat recent and this, I think, should be of some concern.
You don't say how often this happens, but even if it's fairly infrequent, you should still have it evaluated by a doctor. Could be nothing more than a need for glasses, but I don't think you should ignore it. And I don't think your "overreacting" to this.
Please see your doctor.
Peace
Greenlydia