As you many have experienced, an awful lot can 'happen' or 'come up' during a Conscious Connected Breathwork session, so what should you do afterwards? I often recommend first things first, have something to eat and ideally if you can, go for a walk (ideally in natural surroundings if possible). Those two things will 'ground' you, or, bring you back into your body, back into yourself.
Another powerful thing to do for yourself after a session is to pull out a notebook and pen and write. Write down whatever comes to you. This is sometimes called free writing. A friend taught it to me based on a book and programme called The Artist's Way. All you need to do is set a timer for say 10-15 minutes, put pen to paper and literally just write. And even if you don't know what to write, begin just by writing that (I don't know what to write). As you remain in the flow state, just keep going. Don't allow yourself to stop, get into the flow of it all and just see what comes out onto the page. Allow the words to fall out of you, no one is going to read this other than you (and you can even get rid of it after, if you'd prefer).
If you'd rather have some prompts to work with, try some of the following to begin your journaling:
During my Breathwork session,in my body I physically felt...
During my Breathwork session, emotionally I felt...
During my Breathwork session, spiritually (or, energetically) I felt..
I don't want to be too prescriptive here as I'd much rather it came from you. Ideally do this right after your session, but it's ok too if there is a delay in doing this - just do it when it feels right and ok. Good luck.