Ok, a bit more theory, mostly mine. It's all a bit unstructured. Please bear with me.

First a bit more about the DSM.

They also added the specifier "with anxious distress" which can apply to basically everything. But it implies that some people have more anxiety, having the same type of disorder, than others. I guess.

Specifiers are added because the DSM is basically a mess, hinging on two ideas or approaches: a categorical and a dimensional.

A dimensional approach can be more specific, but it can also be less specific if specific categories are replaced by less specific ones (so not really dimensions or a binary dimension, which is a category), which, more like sets, can be combined.

In other words, in making concessions, the DSM-5 might have made things worse, not better.

The chair of the DSM-IV BP working group is developing a competing, dimensional theory, just to show you how political all this is.

Never create a theory (or try to unify theories) with a committee.

So here's my dimensional theory.

I believe anxiety, sensitivity/fear and susceptibility for psychosis together determine the length and severity of mania and depression. These things are not independent, but this way its more like the DSM theory.

I think they can all be reduced to one dimension. But that's not relevant yet.

If all are high, you have a very extreme mixed state, going from one extreme to the other, aspects from one mood overlapping with the other.

Less susceptibility for psychosis causes less severe mixed states. Less sensitivity/fear causes longer cycles (so it might not be "mixed"). Less anxiety causes less severity.

Anxiety causes depression, no anxiety mania.

To reduce these three factors: the more susceptible to psychosis, the more anxiety (two types) and sensitivity/fear. But in a complex way I won't go into now.

It's not completely independent as one dimension either: it depends on your personality, opportunities and other environmental factors.

To come to a conclusion: other than what they imply/propose by making the DSM as it is, I think anxiety and how fast mood states are mixed are actually (very) much dependent on the susceptibility for psychosis, so I believe that if you have a mixed state, you likely have BP-I, but it may be BP-II together with something else that increases anxiety, environmental and/or having to do with you personality.

Considering what you described earlier, elsewhere, I think at least your personality adds to the anxiety (caused by confusion basically).