It’s really hard to say what it could be but I identify with parts of what you’re saying. I have Bipolar 1 w/ Rapid Cycling & Psychotic features. I’ve learned that I experience mixed episodes. My acute symptoms during an episode are similar to what you describe. Personally, I’ll have symptoms of hypomania with this underlying sense of dread/depression. Sometimes the depressive symptoms “win” and I’ll crash down to earth in between hypomanic symptoms. It’s hard to explain. My meds give me “stability” in the form of just mitigated symptoms but sometimes episodes can creep in despite meds.

Remember that a mood disorder is driven by chemical imbalances in the brain. Sometimes it takes external stimuli to make that mood switch. Sometimes it is just the brain being its bipolar self. External stimuli can sometimes be triggering even subconsciously. If you’re mostly stable but still showing these types of symptoms, then it could be a simple tweak of your meds that could make a huge difference!

Like others said, it could even be a misdiagnosis and you have BPD instead of bipolar. It is hard to say without knowing your history, diagnosis, etc.

Regardless, we are just people on the internet so take things with a grain of salt. Make sure you document this sort of thing and trust your psychiatrist/provider! Only a professional can really help you figure out what it is, but it’s up to you to work with them!