I have a long history of PCS. For the past few months my symptoms have been relatively under control. I was having occasional headache flairs and nearly constant brain fog as my 2 main symptoms.

Recently however, I have had an onset of new-ish symptoms which have now persisted for more than a week and have been quite debilitating. The main symptoms is a sense of disequilibrium/dizziness where I am constantly feeling woozy and off balance. This is NOT vertigo or lightheadedness. It is a very uncomfortable feeling in my brain which I find very difficult to describe. It is almost like I am on a boat/ everything around me is always slightly off balance/off center and my own body doesnt feel fully in balance. It also makes me feel slightly nauseous, especially when I move around too much (ex. looking around and moving my head a lot or when driving in the car). But I even feel this slight nauseous/sick feeling just from sitting sometimes. This symptoms has also caused a lot more debilitating brain fog as the combination of dizziness and brain fog makes it almost impossible to concentrate on any work.
I have also been having new onset of tinnitus, which is something I have never had before. These symptoms are present 24/7 with relatively constant intensity. From the moment I wake up I can already feel the symptoms when my eyes are closed in bed to the moment I go to sleep.

I am trying to pinpoint what could have caused these symptoms.

At first I thought it might be a symptom flair up because I went on a short roadtrip in the days before the symptoms started. We drove 12 hours over 3 days. I was sitting in the back of the car and there were a few dips or bumps in the road which jostled my neck. They caused some anxiety but I got over the stress quite fast as they were not severe jolts and I told myself that these were jolts that I should be able to tolerate as they definitely would not have caused stress before my PCS journey. I was also doing my best to brace my neck for these jolts when in the car as I could see them coming. The symptoms started 2 days after the roadtrip.

I have also just started topical 5% minoxidil, which is a foam that you spread over your scalp 1x daily to treat hair loss. It is a vasodilator and a blood pressure lowering medication when taken in its oral form. However, in the topical form, only 1% is supposedly absorbed into the bloodstream and it is not supposed to cause a lot of systemic side effects. I had been using the minoxidil for 5 days when these symptoms started. After realizing there might be a link, I stopped the minoxidil for 3 days but felt no improvement in my symptoms. I have now been using the minoxidil again for 2 days and am feeling worse:/ I called my dermatologist about this and she assured me that the minoxidil is topical so it should not be causing these side effects. However, I have seen on reddit (r/MinoxidilSideEffects) that quite a few people have developed side effects to topical minoxidil such as fatigue, rapid heart rate/heart palpitations, and tinnitus. I realize though that these people are not the majority and that most people tolerate minoxidil very well.

Apologies for the long post, but I am really at a loss on what is causing these sudden very intense symptoms as neither the minoxidil nor the roadtrip seem like they would be sufficient to trigger these symptoms. I am a bit desperate for a solution as I am truly feeling horrible due to these symptoms.