Many intense emotions....crying...unpleasant sensations..like the stormy sea...there is no clarity just yet...however cant give up the practise no matter how tough the journey is..
This is the exact story "I" am going through. This part of the path is known as Dukkha Nanas aka The Knowledges of Suffering aka Dark Night.
This is the ultimate learning ground where we study the 4 Noble Truths but especially the 2nd and 3rd. Stable Equanimity is the reword. The Dark Night is the building ground of Equanimity.
There are no short cuts. One must fully realise the Dukkha Nanas (get to know them, clearly percieve them), all of them, otherwise one will cycle through them again and again and again.
The way to clearly percieve Dukkha Nanas is by looking at the Three Characteristics as often as possible. All this is to be based on Calm-abiding structure. Calming the bodily formations means being kind towards the body by calming it.
I too feel that sitting is the only way there is even though this experience is wrecking "me".
Note; who is this which is feeling so bad? Is it "me"? If not "me" than who is this one suffering?? What is this suffering phenomena? Is there a "me"??
This is the way of contemplating the Non-self Characteristic.
Suffering exists because we cling to desire and aversion.
Once we stop clinging to phenomena by clearly percieving The Three Characteristics of all Arisings Suffering stops also.
Equanimity is not something one can Fabricate. It must be actualy realised in the melting oven of the Dark Night. Otherwise, intelectualy forced equanimity is nothing more but a fabricated suppressing of emotions, which is Ignorance. Dont go there.
Remaining in the Dark Night is chalenging. It must like surfing the huge waves. Aline on the board and a huge heavy wave crushing behind your back just about to swollow you into the abyss.
But who is this "me" percieving it thid way?? Who is this "I"??
Contemplate it, dont think it, contemplate it, keep the question alive and let the answer come in an abstract yet profound form.
I suggest to familiarise yourself with Daniel Ingram's book Mastering The Core Teachings of the Buddha and to start building a Calm base by starting your practice as Calm-abiding(as suggested in our article). Since you know Vipassana, insight will come on its own once the body is calm.
Calm body will produce Dopamine and Serotonin which will help counteracting Adrenaline and Cortisol. Such body will calm the agitated mind and Vipassana can be percieved with Calm Clarity.
Do not underestimate Calm-abiding. It is an actual way to show kindness towards your body-mind.
Dark Night is dark because the false sense of Self is building Aversion towards the dark emotions and by Desiering peace, calm, relaxation, better times, better meditation, etc.
The lecture is to see the Suffering as it Is. It is transient, unsatisfactory and non-self.
Once this is Actualy, not Intelectually, but Actualy percieved, Equanimity will be the end product. One does not chase Equanimity, it happens on its own as a result of crearly percieving the Three Characteristics.
Welcome to the club

Your not alone in this
Be well